Debian GNU/Linux Installation Guide

May 19, 2024

Debian GNU/Linux Installation Guide
Copyright © 2004 – 2023 the Debian Installer teamThis manual is free software; you may redistribute it and/or modify it under the terms of the GNU General Public
License. Please refer to the license in Appendix F.
Build version of this manual: 20230508+deb12u1.

iContents
1

Welcome to Debian
1.1 What is Debian? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.2 What is GNU/Linux? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.3 What is Debian GNU/Linux? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.4 What is the Debian Installer? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.5 Getting Debian . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.6 Getting the Newest Version of This Document . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.7 Organization of This Document . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.8 About Copyrights and Software Licenses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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System Requirements
2.1 Supported Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.1.1 Supported Architectures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.1.2 Three different ARM ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.1.3 Variations in ARM CPU designs and support complexity . . . . . . . . . . . . . . . . . .
2.1.4 Platforms supported by Debian/arm64 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.1.4.1 Other platforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.1.5 Multiple Processors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.1.6 Graphics Hardware Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.1.7 Network Connectivity Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.1.8 Peripherals and Other Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.2 Devices Requiring Firmware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.3 Purchasing Hardware Specifically for GNU/Linux . . . . . . . . . . . . . . . . . . . . . . . . . .
2.3.1 Avoid Proprietary or Closed Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.4 Installation Media . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.4.1 CD-ROM/DVD-ROM/BD-ROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.4.2 USB Memory Stick . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.4.3 Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.4.4 Hard Disk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.4.5 Un*x or GNU system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.4.6 Supported Storage Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5 Memory and Disk Space Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Before Installing Debian GNU/Linux
3.1 Overview of the Installation Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2 Back Up Your Existing Data! . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3 Information You Will Need . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3.1 Documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3.1.1 Installation Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3.1.2 Hardware documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3.2 Finding Sources of Hardware Information . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3.3 Hardware Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.3.3.1 Testing hardware compatibility with a Live-System . . . . . . . . . . . . . . . .
3.3.4 Network Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.4 Meeting Minimum Hardware Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.5 Pre-Partitioning for Multi-Boot Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.6 Pre-Installation Hardware and Operating System Setup . . . . . . . . . . . . . . . . . . . . . . . .
3.6.1 Boot Device Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.6.2 ARM firmware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.6.3 Setting the ethernet MAC address in U-Boot . . . . . . . . . . . . . . . . . . . . . . . . .
3.6.4 Kernel/Initrd/Device-Tree relocation issues in U-Boot . . . . . . . . . . . . . . . . . . . .

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4

Obtaining System Installation Media
4.1 Official Debian GNU/Linux installation images . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.2 Downloading Files from Debian Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.2.1 Where to Find Installation Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.3 Preparing Files for USB Memory Stick Booting . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.3.1 Preparing a USB stick using a hybrid CD/DVD image . . . . . . . . . . . . . . . . . . . .
4.4 Preparing Files for TFTP Net Booting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.4.1 Setting up RARP server . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.4.2 Setting up a DHCP server . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.4.3 Setting up a BOOTP server . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.4.4 Enabling the TFTP Server . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.4.5 Move TFTP Images Into Place . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.5 Automatic Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.5.1 Automatic Installation Using the Debian Installer . . . . . . . . . . . . . . . . . . . . . . .
4.6 Verifying the integrity of installation files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Booting the Installation System
5.1 Booting the Installer on 64-bit ARM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.1.1 Console configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.1.2 Juno Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.1.3 Applied Micro Mustang Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.1.4 Booting by TFTP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.1.4.1 TFTP-booting in U-Boot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.1.5 Booting from USB Memory Stick with UEFI . . . . . . . . . . . . . . . . . . . . . . . . .
5.1.6 The Graphical Installer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.2 Accessibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.2.1 Installer front-end . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.2.2 Board Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.2.3 High-Contrast Theme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.2.4 Zoom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.2.5 Expert install, rescue mode, automated install . . . . . . . . . . . . . . . . . . . . . . . .
5.2.6 Accessibility of the installed system . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.3 Boot Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.3.1 Boot console . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.3.2 Debian Installer Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.3.3 Using boot parameters to answer questions . . . . . . . . . . . . . . . . . . . . . . . . . .
5.3.4 Passing parameters to kernel modules . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.3.5 Blacklisting kernel modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.4 Troubleshooting the Installation Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.4.1 Reliability of optical media . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.4.1.1 Common issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.4.1.2 How to investigate and maybe solve issues . . . . . . . . . . . . . . . . . . . . .
5.4.2 Boot Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.4.3 Interpreting the Kernel Startup Messages . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.4.4 Reporting Installation Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.4.5 Submitting Installation Reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Using the Debian Installer
6.1 How the Installer Works . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.1.1 Using the graphical installer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.2 Components Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3 Using Individual Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.1 Setting up Debian Installer and Hardware Configuration . . . . . . . . . . . . . . . . . . .
6.3.1.1 Check available memory / low memory mode . . . . . . . . . . . . . . . . . . .
6.3.1.2 Selecting Localization Options . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.1.3 Choosing a Keyboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.1.4 Looking for the Debian Installer ISO Image . . . . . . . . . . . . . . . . . . . .
6.3.1.5 Configuring the Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.1.5.1 Automatic network configuration . . . . . . . . . . . . . . . . . . . .

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6.3.1.5.2 Manual network configuration . . . . . . . . . . . . . . . . . . . . . .
6.3.1.5.3 IPv4 and IPv6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.2 Setting Up Users And Passwords . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.2.1 Set the Root Password . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.2.2 Create an Ordinary User . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.3 Configuring the Clock and Time Zone . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.4 Partitioning and Mount Point Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.4.1 Supported partitioning options . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.4.2 Guided Partitioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.4.3 Manual Partitioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.4.4 Configuring Multidisk Devices (Software RAID) . . . . . . . . . . . . . . . . .
6.3.4.5 Configuring the Logical Volume Manager (LVM) . . . . . . . . . . . . . . . . .
6.3.4.6 Configuring Encrypted Volumes . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.5 Installing the Base System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.6 Installing Additional Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.6.1 Configuring apt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.6.1.1 Installing from more than one CD or DVD image . . . . . . . . . . . .
6.3.6.1.2 Using a network mirror . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.6.1.3 Choosing a network mirror . . . . . . . . . . . . . . . . . . . . . . .
6.3.6.2 Selecting and Installing Software . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.7 Making Your System Bootable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.7.1 Detecting other operating systems . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.7.2 Making the system bootable with flash-kernel . . . . . . . . . . . . . . . . . . .
6.3.7.3 Continue Without Boot Loader . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.8 Finishing the Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.8.1 Setting the System Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.8.2 Reboot the System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.9 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.9.1 Saving the installation logs . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.9.2 Using the Shell and Viewing the Logs . . . . . . . . . . . . . . . . . . . . . . .
6.3.10 Installation over network-console . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Loading Missing Firmware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.4.1 Preparing a medium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.4.2 Firmware and the Installed System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.4.3 Completing the Installed System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Customization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.5.1 Installing an alternative init system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Booting Into Your New Debian System
7.1 The Moment of Truth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7.2 Mounting encrypted volumes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7.2.1 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7.3 Log In . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Next Steps and Where to Go From Here
8.1 Shutting down the system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.2 Orienting Yourself to Debian . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.2.1 Debian Packaging System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.2.2 Additional Software Available for Debian . . . . . . . . . . . . . . . . . . . . . . . . . .
8.2.3 Application Version Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.2.4 Cron Job Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.3 Further Reading and Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.4 Setting Up Your System To Use E-Mail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.4.1 Default E-Mail Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.4.2 Sending E-Mails Outside The System . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.4.3 Configuring the Exim4 Mail Transport Agent . . . . . . . . . . . . . . . . . . . . . . . .
8.5 Compiling a New Kernel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.6 Recovering a Broken System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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A Installation Howto
A.1 Preliminaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A.2 Booting the installer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A.2.1 Optical disc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A.2.2 USB memory stick . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A.2.3 Booting from network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A.2.4 Booting from hard disk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A.3 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A.4 Send us an installation report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A.5 And finally… . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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B Automating the installation using preseeding
B.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.1.1 Preseeding methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.1.2 Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.2 Using preseeding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.2.1 Loading the preconfiguration file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.2.2 Using boot parameters to preseed questions . . . . . . . . . . . . . . . . . . . . . . . . .
B.2.3 Auto mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.2.4 Aliases useful with preseeding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.2.5 Examples of boot prompt preseeding . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.2.6 Using a DHCP server to specify preconfiguration files . . . . . . . . . . . . . . . . . . . .
B.3 Creating a preconfiguration file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.4 Contents of the preconfiguration file (for bookworm) . . . . . . . . . . . . . . . . . . . . . . . . .
B.4.1 Localization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.4.2 Network configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.4.3 Network console . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.4.4 Mirror settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.4.5 Account setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.4.6 Clock and time zone setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.4.7 Partitioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.4.7.1 Partitioning example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.4.7.2 Partitioning using RAID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.4.7.3 Controlling how partitions are mounted . . . . . . . . . . . . . . . . . . . . . .
B.4.8 Base system installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.4.9 Apt setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.4.10 Package selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.4.11 Finishing up the installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.4.12 Preseeding other packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.5 Advanced options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
B.5.1 Running custom commands during the installation . . . . . . . . . . . . . . . . . . . . . .
B.5.2 Using preseeding to change default values . . . . . . . . . . . . . . . . . . . . . . . . . .
B.5.3 Chainloading preconfiguration files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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C Partitioning for Debian
C.1 Deciding on Debian Partitions and Sizes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C.2 The Directory Tree . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C.3 Recommended Partitioning Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C.4 Device Names in Linux . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C.5 Debian Partitioning Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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D Random Bits
D.1 Linux Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D.1.1 Setting Up Your Mouse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D.2 Disk Space Needed for Tasks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D.3 Installing Debian GNU/Linux from a Unix/Linux System . . . . . . . . . . . . . . . . . . . . . .
D.3.1 Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D.3.2 Install debootstrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D.3.3 Run debootstrap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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v

CONTENTS

D.3.4 Configure The Base System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D.3.4.1 Create device files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D.3.4.2 Mount Partitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D.3.4.3 Setting Timezone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D.3.4.4 Configure Networking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D.3.4.5 Configure Apt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D.3.4.6 Configure Locales and Keyboard . . . . . . . . . . . . . . . . . . . . . . . . . .
D.3.5 Install a Kernel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D.3.6 Set up the Boot Loader . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D.3.7 Remote access: Installing SSH and setting up access . . . . . . . . . . . . . . . . . . . . .
D.3.8 Finishing touches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D.4 Installing Debian GNU/Linux using PPP over Ethernet (PPPoE) . . . . . . . . . . . . . . . . . . .

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E Administrivia
E.1 About This Document . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
E.2 Contributing to This Document . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
E.3 Major Contributions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
E.4 Trademark Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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F GNU General Public License
F.1 Preamble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
F.2 GNU GENERAL PUBLIC LICENSE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
F.3 How to Apply These Terms to Your New Programs . . . . . . . . . . . . . . . . . . . . . . . . . .

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vi

List of Tables
3

Before Installing Debian GNU/Linux
3.1 Hardware Information Helpful for an Install . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2 Recommended Minimum System Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . .

vii

12
13

Abstract
This document contains installation instructions for the Debian GNU/Linux 12 system (codename “bookworm”),
for the 64-bit ARM (“arm64”) architecture. It also contains pointers to more information and information on how tomake the most of your new Debian system.

Installing Debian GNU/Linux 12 for arm64
We are delighted that you have decided to try Debian, and are sure that you will find that Debian’s GNU/Linux distribution is unique. Debian GNU/Linux brings together high-quality free software from around the world, integrating it
into a coherent whole. We believe that you will find that the result is truly more than the sum of the parts.
We understand that many of you want to install Debian without reading this manual, and the Debian installer isdesigned to make this possible. If you don’t have time to read the whole Installation Guide right now, we recommendthat you read the Installation Howto, which will walk you through the basic installation process, and links to the manual
for more advanced topics or for when things go wrong. The Installation Howto can be found in Appendix A.
With that said, we hope that you have the time to read most of this manual, and doing so will lead to a more
informed and likely more successful installation experience.

ix

Chapter 1

Welcome to DebianThis chapter provides an overview of the Debian Project and Debian GNU/Linux. If you already know about the
Debian Project’s history and the Debian GNU/Linux distribution, feel free to skip to the next chapter.

1.1

What is Debian?

Debian is an all-volunteer organization dedicated to developing free software and promoting the ideals of the Free
Software community. The Debian Project began in 1993, when Ian Murdock issued an open invitation to softwaredevelopers to contribute to a complete and coherent software distribution based on the relatively new Linux kernel.
That relatively small band of dedicated enthusiasts, originally funded by the Free Software Foundation and influenced
by the GNU philosophy, has grown over the years into an organization of around 1000 Debian Developers.
Debian Developers are involved in a variety of activities, including Web and FTP site administration, graphic
design, legal analysis of software licenses, writing documentation, and, of course, maintaining software packages.
In the interest of communicating our philosophy and attracting developers who believe in the principles that Debianstands for, the Debian Project has published a number of documents that outline our values and serve as guides towhat it means to be a Debian Developer:• The Debian Social Contract is a statement of Debian’s commitments to the Free Software Community. Anyone
who agrees to abide to the Social Contract may become a maintainer. Any maintainer can introduce newsoftware into Debian — provided that the software meets our criteria for being free, and the package follows
our quality standards.
• The Debian Free Software Guidelines are a clear and concise statement of Debian’s criteria for free software.
The DFSG is a very influential document in the Free Software Movement, and was the foundation of the The
Open Source Definition.
• The Debian Policy Manual is an extensive specification of the Debian Project’s standards of quality.
Debian developers are also involved in a number of other projects; some specific to Debian, others involving someor all of the Linux community. Some examples include:• The Filesystem Hierarchy Standard (FHS) is an effort to standardize the layout of the Linux file system. The
FHS will allow software developers to concentrate their efforts on designing programs, without having to worry
about how the package will be installed in different GNU/Linux distributions.
• Debian Jr. is an internal project, aimed at making sure Debian has something to offer to our youngest users.
For more general information about Debian, see the Debian FAQ.

1.2

What is GNU/Linux?

GNU/Linux is an operating system: a series of programs that let you interact with your computer and run otherprograms.
An operating system consists of various fundamental programs which are needed by your computer so that it cancommunicate and receive instructions from users; read and write data to hard disks, tapes, and printers; control the useof memory; and run other software. The most important part of an operating system is the kernel. In a GNU/Linux1

CHAPTER 1. WELCOME TO DEBIAN

1.3. WHAT IS DEBIAN GNU/LINUX?

system, Linux is the kernel component. The rest of the system consists of other programs, many of which were written
by or for the GNU Project. Because the Linux kernel alone does not form a working operating system, we prefer to
use the term “GNU/Linux” to refer to systems that many people casually refer to as “Linux”.
GNU/Linux is modelled on the Unix operating system. From the start, GNU/Linux was designed to be a multitasking, multi-user system. These facts are enough to make GNU/Linux different from other well-known operating
systems. However, GNU/Linux is even more different than you might imagine. In contrast to other operating systems,
nobody owns GNU/Linux. Much of its development is done by unpaid volunteers.
Development of what later became GNU/Linux began in 1984, when the Free Software Foundation began development of a free Unix-like operating system called GNU.
The GNU Project has developed a comprehensive set of free software tools for use with Unix™ and Unix-like
operating systems such as GNU/Linux. These tools enable users to perform tasks ranging from the mundane (such as
copying or removing files from the system) to the arcane (such as writing and compiling programs or doing sophisticated editing in a variety of document formats).
While many groups and individuals have contributed to GNU/Linux, the largest single contributor is still the Free
Software Foundation, which created not only most of the tools used in GNU/Linux, but also the philosophy and thecommunity that made GNU/Linux possible.
The Linux kernel first appeared in 1991, when a Finnish computing science student named Linus Torvalds announced an early version of a replacement kernel for Minix to the Usenet newsgroup comp.os.minix. See LinuxInternational’s Linux History Page.
Linus Torvalds continues to coordinate the work of several hundred developers with the help of a number ofsubsystem maintainers. There is an official website for the Linux kernel. Information about the linux-kernel
mailing list can be found on the linux-kernel mailing list FAQ.
GNU/Linux users have immense freedom of choice in their software. For example, they can choose from a dozen
different command line shells and several graphical desktops. This selection is often bewildering to users of otheroperating systems, who are not used to thinking of the command line or desktop as something that they can change.
GNU/Linux is also less likely to crash, better able to run more than one program at the same time, and moresecure than many operating systems. With these advantages, Linux is the fastest growing operating system in theserver market. More recently, Linux has begun to be popular among home and business users as well.

1.3

What is Debian GNU/Linux?

The combination of Debian’s philosophy and methodology and the GNU tools, the Linux kernel, and other important
free software, form a unique software distribution called Debian GNU/Linux. This distribution is made up of a large
number of software packages. Each package in the distribution contains executables, scripts, documentation, andconfiguration information, and has a maintainer who is primarily responsible for keeping the package up-to-date,
tracking bug reports, and communicating with the upstream author(s) of the packaged software. Our extremely large
user base, combined with our bug tracking system ensures that problems are found and fixed quickly.
Debian’s attention to detail allows us to produce a high-quality, stable, and scalable distribution. Installations canbe easily configured to serve many roles, from stripped-down firewalls to desktop scientific workstations to high-end
network servers.
Debian is especially popular among advanced users because of its technical excellence and its deep commitment
to the needs and expectations of the Linux community. Debian also introduced many features to Linux that are now
commonplace.
For example, Debian was the first Linux distribution to include a package management system for easy installation
and removal of software. It was also the first Linux distribution that could be upgraded without requiring reinstallation.
Debian continues to be a leader in Linux development. Its development process is an example of just how well
the Open Source development model can work — even for very complex tasks such as building and maintaining acomplete operating system.
The feature that most distinguishes Debian from other Linux distributions is its package management system.
These tools give the administrator of a Debian system complete control over the packages installed on that system,
including the ability to install a single package or automatically update the entire operating system. Individual packages
can also be protected from being updated. You can even tell the package management system about software you havecompiled yourself and what dependencies it fulfills.
To protect your system against “Trojan horses” and other malevolent software, Debian’s servers verify that uploaded packages come from their registered Debian maintainers. Debian packagers also take great care to configure
their packages in a secure manner. When security problems in shipped packages do appear, fixes are usually available very quickly. With Debian’s simple update options, security fixes can be downloaded and installed automatically
across the Internet.
2

CHAPTER 1. WELCOME TO DEBIAN

1.4. WHAT IS THE DEBIAN INSTALLER?

The primary, and best, method of getting support for your Debian GNU/Linux system and communicating with
Debian Developers is through the many mailing lists maintained by the Debian Project (there are more than 327 at
this writing). The easiest way to subscribe to one or more of these lists is visit Debian’s mailing list subscription pageand fill out the form you’ll find there.

1.4

What is the Debian Installer?

Debian Installer, also known as “d-i”, is the software system to install a basic working Debian system. A wide rangeof hardware such as embedded devices, laptops, desktops and server machines is supported and a large set of free
software for many purposes is offered.
The installation is conducted by answering a basic set of questions. Also available are an expert mode that allows
to control every aspect of the installation and an advanced feature to perform automated installations. The installedsystem can be used as is or further customized. The installation can be performed from a multitude of sources: USB,
CD/DVD/Blu-Ray or the network. The installer supports localized installations in more than 80 languages.
The installer has its origin in the boot-floppies project, and it was first mentioned by Joey Hess in 2000. Since
then the installation system has been continuously developed by volunteers improving and adding more features.
More information can be found on the Debian Installer page, on the Wiki and on the debian-boot mailing list.

1.5

Getting Debian

For information on how to download Debian GNU/Linux from the Internet or from whom official Debian installation
media can be purchased, see the distribution web page. The list of Debian mirrors contains a full set of official Debianmirrors, so you can easily find the nearest one.
Debian can be upgraded after installation very easily. The installation procedure will help set up the system sothat you can make those upgrades once installation is complete, if need be.

1.6

Getting the Newest Version of This Document

This document is constantly being revised. Be sure to check the Debian 12 pages for any last-minute information
about the 12 release of the Debian GNU/Linux system. Updated versions of this installation manual are also available
from the official Install Manual pages.

1.7

Organization of This Document

This document is meant to serve as a manual for first-time Debian users. It tries to make as few assumptions as possible
about your level of expertise. However, we do assume that you have a general understanding of how the hardware inyour computer works.
Expert users may also find interesting reference information in this document, including minimum installation
sizes, details about the hardware supported by the Debian installation system, and so on. We encourage expert users
to jump around in the document.
In general, this manual is arranged in a linear fashion, walking you through the installation process from start tofinish. Here are the steps in installing Debian GNU/Linux, and the sections of this document which correlate witheach step:
1. Determine whether your hardware meets the requirements for using the installation system, in Chapter 2.
2. Backup your system, perform any necessary planning and hardware configuration prior to installing Debian, in
Chapter 3. If you are preparing a multi-boot system, you may need to create partitionable space on your harddisk for Debian to use.
3. In Chapter 4, you will obtain the necessary installation files for your method of installation.
4. The next Chapter 5 describes booting into the installation system. This chapter also discusses troubleshooting
procedures in case you have problems with this step.
5. Perform the actual installation according to Chapter 6. This involves choosing your language, configuring peripheral driver modules, configuring your network connection, so that remaining installation files can be obtained directly from a Debian server (if you are not installing from a set of CD/DVD installation images),3

CHAPTER 1. WELCOME TO DEBIAN

1.8. ABOUT COPYRIGHTS AND SOFTWARE LICENSES

partitioning your hard drives and installation of a base system, then selection and installation of tasks. (Somebackground about setting up the partitions for your Debian system is explained in Appendix C.)
6. Boot into your newly installed base system, from Chapter 7.
Once you’ve got your system installed, you can read Chapter 8. That chapter explains where to look to find more
information about Unix and Debian, and how to replace your kernel.
Finally, information about this document and how to contribute to it may be found in Appendix E.

1.8

About Copyrights and Software Licenses

We’re sure that you’ve read some of the licenses that come with most commercial software — they usually say that you
can only use one copy of the software on a single computer. This system’s license isn’t like that at all. We encourage
you to put a copy of Debian GNU/Linux on every computer in your school or place of business. Lend your installation
media to your friends and help them install it on their computers! You can even make thousands of copies and sellthem — albeit with a few restrictions. Your freedom to install and use the system comes directly from Debian being
based on free software.
Calling software free doesn’t mean that the software isn’t copyrighted, and it doesn’t mean that installation media
containing that software must be distributed at no charge. Free software, in part, means that the licenses of individual
programs do not require you to pay for the privilege of distributing or using those programs. Free software also meansthat not only may anyone extend, adapt, and modify the software, but that they may distribute the results of their work
as well.

NOTE
The Debian project, as a pragmatic concession to its users, does make some packages available that do not meet our criteria for being free. These packages are notpart of the official distribution, however, and are only available from the contrib or
non-free areas of Debian mirrors or on third-party CD/DVD-ROMs; see the Debian FAQ, under “The Debian FTP archives”, for more information about the layout
and contents of the archives.
Many of the programs in the system are licensed under the GNU General Public License, often simply referred
to as “the GPL”. The GPL requires you to make the source code of the programs available whenever you distributea binary copy of the program; that provision of the license ensures that any user will be able to modify the software.
Because of this provision, the source code¹ for all such programs is available in the Debian system.
There are several other forms of copyright statements and software licenses used on the programs in Debian. You
can find the copyrights and licenses for every package installed on your system by looking in the file /usr/share/
doc/package-name/copyright once you’ve installed a package on your system.
For more information about licenses and how Debian determines whether software is free enough to be includedin the main distribution, see the Debian Free Software Guidelines.
The most important legal notice is that this software comes with no warranties. The programmers who havecreated this software have done so for the benefit of the community. No guarantee is made as to the suitability of thesoftware for any given purpose. However, since the software is free, you are empowered to modify that software tosuit your needs — and to enjoy the benefits of the changes made by others who have extended the software in thisway.

¹For information on how to locate, unpack, and build binaries from Debian source packages, see the Debian FAQ, under “Basics of the DebianPackage Management System”.

4Chapter 2

System Requirements
This section contains information about what hardware you need to get started with Debian. You will also find links
to further information about hardware supported by GNU and Linux.

2.1

Supported Hardware

Debian does not impose hardware requirements beyond the requirements of the Linux or kFreeBSD kernel and the
GNU tool-sets. Therefore, any architecture or platform to which the Linux or kFreeBSD kernel, libc, gcc, etc.
have been ported, and for which a Debian port exists, can run Debian. Please refer to the Ports pages at https://www.debian.org/ports/arm/ for more details on 64-bit ARM architecture systems which have been tested
with Debian GNU/Linux.
Rather than attempting to describe all the different hardware configurations which are supported for 64-bit ARM,
this section contains general information and pointers to where additional information can be found.

2.1.1

Supported Architectures

Debian GNU/Linux 12 supports 9 major architectures and several variations of each architecture known as “flavors”.
Architecture
AMD64 & Intel 64

Debian Designation
amd64

Intel x86-based

i386

ARM

armel

ARM with hardware
FPU
64bit ARM

armhf

Subarchitecture

Flavordefault x86 machines
Xen PV domains only
Marvell Kirkwood andOrion

defaultxen

multiplatform

armmp

MIPS Malta
Cavium Octeon
Loongson 3
MIPS Malta
Cavium Octeon
Loongson 3
IBM POWER8 or newer
machines
IPL from VM-reader
and DASD

5kc-maltaocteonloongson-3
4kc-maltaocteonloongson-3

marvell

arm64

64bit MIPS
(little-endian)mips64el

32bit MIPS
(little-endian)mipselPower Systems

ppc64el

64bit IBM S/390

s390x

generic

This document covers installation for the 64-bit ARM architecture using the Linux kernel. If you are looking for
information on any of the other Debian-supported architectures take a look at the Debian-Ports pages.
This is the first official release of Debian GNU/Linux for the 64-bit ARM architecture. We feel that it has provenitself sufficiently to be released. However, because it has not had the exposure (and hence testing by users) that someother architectures have had, you may encounter a few bugs. Use our Bug Tracking System to report any problems;
make sure to mention the fact that the bug is on the 64-bit ARM platform using the Linux kernel. It can be necessary5CHAPTER 2. SYSTEM REQUIREMENTS

2.1. SUPPORTED HARDWARE

to use the debian-arm mailing list as well.

2.1.2

Three different ARM ports

The ARM architecture has evolved over time and modern ARM processors provide features which are not available
in older models. Debian therefore provides three ARM ports to give the best support for a very wide range of different
machines:• Debian/armel targets older 32-bit ARM processors without support for a hardware floating point unit (FPU),• Debian/armhf works only on newer 32-bit ARM processors which implement at least the ARMv7 architecturewith version 3 of the ARM vector floating point specification (VFPv3). It makes use of the extended featuresand performance enhancements available on these models.
• Debian/arm64 works on 64-bit ARM processors which implement at least the ARMv8 architecture.
Technically, all currently available ARM CPUs can be run in either endian mode (big or little), but in practice thevast majority use little-endian mode. All of Debian/arm64, Debian/armhf and Debian/armel support only little-endiansystems.

2.1.3

Variations in ARM CPU designs and support complexity

ARM systems are much more heterogeneous than those based on the i386/amd64-based PC architecture, so the
support situation can be much more complicated.
The ARM architecture is used mainly in so-called “system-on-chip” (SoC) designs. These SoCs are designed
by many different companies, often with vastly varying hardware components even for the very basic functionality
required to bring the system up. Older versions of the ARM architecture have seen massive differences from one SoC
to the next, but ARMv8 (arm64) is much more standardised and so is easier for the Linux kernel and other software
to support.
Server versions of ARMv8 hardware are typically configured using the Unified Extensible Firmware Interface(UEFI) and Advanced Configuration and Power Interface (ACPI) standards. These two provide common, deviceindependent ways to boot and configure computer hardware. They are also common in the x86 PC world.

2.1.4

Platforms supported by Debian/arm64

Arm64/AArch64/ARMv8 hardware became available quite late in the Debian Bookworm release cycle so not many
platforms had support merged in the mainline kernel version by the time of this release; this is the main requirement tohave debian-installer working on them. The following platforms are known to be supported by Debian/arm64
in this release. There is only one kernel image, which supports all the listed platforms.
Applied Micro (APM) Mustang/X-Gene The APM Mustang was the first Linux-capable ARMv8 system available.
It uses the X-gene SoC, which has since also been used in other machines. It is an 8-core CPU, with ethernet,
USB and serial. A common form-factor looks just like a desktop PC box, but many other versions are expectedin the future. Most of the hardware is supported in the mainline kernel, but at this point USB support is lacking
in the Bookworm kernel.
ARM Juno Development Platform Juno is a capable development board with a 6-core (2xA57, 4xA53) ARMv8A 800Mhz CPU, Mali (T624) graphics, 8GB DDR3 RAM, Ethernet, USB, Serial. It was designed for systembring-up and power testing so is neither small nor cheap, but was one of the first boards available. All the
on-board hardware is supported in the mainline kernel and in Bookworm.
When using debian-installer on non-UEFI systems, you may have to manually make the system bootable
at the end of the installation, e.g. by running the required commands in a shell started from within debian-installer.
flash-kernel knows how to set up an X-Gene system booting with U-Boot.
2.1.4.1

Other platforms

The multiplatform support in the arm64 Linux kernel may also allow running debian-installer on arm64
systems not explicitly listed above. So long as the kernel used by debian-installer has support for the target
system’s components, and a device-tree file for that target is available, a new target system may work just fine. In thesecases, the installer can usually provide a working installation, and so long as UEFI is in use, it should be able to makethe system bootable as well. If UEFI is not used you may also need to perform some manual configuration steps tomake the system bootable.
6CHAPTER 2. SYSTEM REQUIREMENTS

2.1.5

2.2. DEVICES REQUIRING FIRMWARE

Multiple Processors

Multiprocessor support — also called “symmetric multiprocessing” or SMP — is available for this architecture. Having multiple processors in a computer was originally only an issue for high-end server systems but has become common
in recent years nearly everywhere with the introduction of so called “multi-core” processors. These contain two or
more processor units, called “cores”, in one physical chip.
The standard Debian 12 kernel image has been compiled with SMP support. It is also usable on non-SMP systems
without problems.

2.1.6

Graphics Hardware Support

Debian’s support for graphical interfaces is determined by the underlying support found in X.Org’s X11 system, and thekernel. Basic framebuffer graphics is provided by the kernel, whilst desktop environments use X11. Whether advanced
graphics card features such as 3D-hardware acceleration or hardware-accelerated video are available, depends on theactual graphics hardware used in the system and in some cases on the installation of additional “firmware” blobs (seeSection 2.2).
Nearly all ARM machines have the graphics hardware built-in, rather than being on a plug-in card. Some machines
do have expansion slots which will take graphics cards, but that is a rarity. Hardware designed to be headless with nographics at all is quite common. Whilst basic framebuffer video provided by the kernel should work on all devices thathave graphics, fast 3D graphics invariably needs binary drivers to work. The situation is changing quickly but at thetime of the bookworm release free drivers for nouveau (Nvidia Tegra K1 SoC) and freedreno (Qualcomm Snapdragon
SoCs) are available in the release. Other hardware needs non-free drivers from 3rd parties.
Details on supported graphics hardware and pointing devices can be found at https://wiki.freedesktop.
org/xorg/. Debian 12 ships with X.Org version 7.7.

2.1.7

Network Connectivity Hardware

Almost any network interface card (NIC) supported by the Linux kernel should also be supported by the installation
system; drivers should normally be loaded automatically.
On 64-bit ARM, most built-in Ethernet devices are supported and modules for additional PCI and USB devices
are provided.

2.1.8

Peripherals and Other Hardware

Linux supports a large variety of hardware devices such as mice, printers, scanners, PCMCIA/CardBus/ExpressCard
and USB devices. However, most of these devices are not required while installing the system.

2.2

Devices Requiring Firmware

Besides the availability of a device driver, some hardware also requires so-called firmware or microcode to be loaded
into the device before it can become operational. This is most common for network interface cards (especially wireless
NICs), but for example some USB devices and even some hard disk controllers also require firmware.
With many graphics cards, basic functionality is available without additional firmware, but the use of advanced
features requires an appropriate firmware file to be installed in the system.
On many older devices which require firmware to work, the firmware file was permanently placed in an EEPROM/Flash chip on the device itself by the manufacturer. Nowadays most new devices do not have the firmware
embedded this way anymore, so the firmware file must be uploaded into the device by the host operating system every
time the system boots.
In most cases firmware is non-free according to the criteria used by the Debian GNU/Linux project and thus cannot
be included in the main distribution. If the device driver itself is included in the distribution and if Debian GNU/Linuxlegally can distribute the firmware, it will often be available as a separate package from the non-free-firmware sectionof the archive (prior to Debian GNU/Linux 12.0: from the non-free section).
However, this does not mean that such hardware cannot be used during installation. Starting with Debian GNU/Linux
12.0, following the 2022 General Resolution about non-free firmware, official installation images can include nonfree firmware packages. By default, debian-installer will detect required firmware (based on kernel logs andmodalias information), and install the relevant packages if they are found on an installation medium (e.g. on the
netinst). The package manager gets automatically configured with the matching components so that those packages
get security updates. This usually means that the non-free-firmware component gets enabled, in addition to main.

7

CHAPTER 2. SYSTEM REQUIREMENTS

2.3. PURCHASING HARDWARE SPECIFICALLY …

Users who wish to disable firmware lookup entirely can do so by setting the firmware=never boot parameter.
It’s an alias for the longer hw-detect/firmware-lookup=never form.
Unless firmware lookup is disabled entirely, debian-installer still supports loading firmware files or packages containing firmware from a removable medium, such as a USB stick. See Section 6.4 for detailed information
on how to load firmware files or packages during the installation. Note that debian-installer is less likely toprompt for firmware files now that non-free firmware packages can be included on installation images.
If the debian-installer prompts for a firmware file and you do not have this firmware file available or do notwant to install a non-free firmware file on your system, you can try to proceed without loading the firmware. There areseveral cases where a driver prompts for additional firmware because it may be needed under certain circumstances,
but the device does work without it on most systems (this e.g. happens with certain network cards using the tg3 driver).

2.3

Purchasing Hardware Specifically for GNU/Linux

There are several vendors, who ship systems with Debian or other distributions of GNU/Linux pre-installed. Youmight pay more for the privilege, but it does buy a level of peace of mind, since you can be sure that the hardware iswell-supported by GNU/Linux.
Whether or not you are purchasing a system with Linux bundled, or even a used system, it is still important tocheck that your hardware is supported by the Linux kernel. Check if your hardware is listed in the references foundabove. Let your salesperson (if any) know that you’re shopping for a Linux system. Support Linux-friendly hardware
vendors.

2.3.1

Avoid Proprietary or Closed Hardware

Some hardware manufacturers simply won’t tell us how to write drivers for their hardware. Others won’t allow us
access to the documentation without a non-disclosure agreement that would prevent us from releasing the driver’s
source code, which is one of the central elements of free software. Since we haven’t been granted access to usable
documentation on these devices, they simply won’t work under Linux.
In many cases there are standards (or at least some de-facto standards) describing how an operating system and its
device drivers communicate with a certain class of devices. All devices which comply to such a (de-facto-)standard canbe used with a single generic device driver and no device-specific drivers are required. With some kinds of hardware(e.g. USB “Human Interface Devices”, i.e. keyboards, mice, etc., and USB mass storage devices like USB flash disks
and memory card readers) this works very well and practically every device sold in the market is standards-compliant.
In other fields, among them e.g. printers, this is unfortunately not the case. While there are many printers which
can be addressed via a small set of (de-facto-)standard control languages and therefore can be made to work without
problems in any operating system, there are quite a few models which only understand proprietary control commands
for which no usable documentation is available and therefore either cannot be used at all on free operating systems or
can only be used with a vendor-supplied closed-source driver.
Even if there is a vendor-provided closed-source driver for such hardware when purchasing the device, the practicallifespan of the device is limited by driver availability. Nowadays product cycles have become short and it is notuncommon that a short time after a consumer device has ceased production, no driver updates get made available any
more by the manufacturer. If the old closed-source driver does not work anymore after a system update, an otherwise
perfectly working device becomes unusable due to lacking driver support and there is nothing that can be done in thiscase. You should therefore avoid buying closed hardware in the first place, regardless of the operating system you
want to use it with.
You can help improve this situation by encouraging manufacturers of closed hardware to release the documentationand other resources necessary for us to provide free drivers for their hardware.

2.4

Installation MediaThis section will help you determine which different media types you can use to install Debian. There is a wholechapter devoted to media, Chapter 4, which lists the advantages and disadvantages of each media type. You may want
to refer back to this page once you reach that section.

2.4.1

CD-ROM/DVD-ROM/BD-ROM

Installation from optical disc is supported for most architectures.

8CHAPTER 2. SYSTEM REQUIREMENTS

2.4.2

2.5. MEMORY AND DISK SPACE REQUIREMENTS

USB Memory StickUSB flash disks a.k.a. USB memory sticks have become a commonly used and cheap storage device. Most modern
computer systems also allow booting the debian-installer from such a stick. Many modern computer systems,
in particular netbooks and thin laptops, do not have an optical drive anymore at all and booting from USB media is
the standard way of installing a new operating system on them.

2.4.3

Network

The network can be used during the installation to retrieve files needed for the installation. Whether the network isused or not depends on the installation method you choose and your answers to certain questions that will be asked
during the installation. The installation system supports most types of network connections (including PPPoE, but not
ISDN or PPP), via either HTTP or FTP. After the installation is completed, you can also configure your system touse ISDN and PPP.
You can also boot the installation system over the network without needing any local media like CDs/DVDs or
USB sticks. If you already have a netboot-infrastructure available (i.e. you are already running DHCP and TFTP
services in your network), this allows an easy and fast deployment of a large number of machines. Setting up thenecessary infrastructure requires a certain level of technical experience, so this is not recommended for novice users.
Diskless installation, using network booting from a local area network and NFS-mounting of all local filesystems,
is another option.

2.4.4

Hard Disk

Booting the installation system directly from a hard disk is another option for many architectures. This will require
some other operating system to load the installer onto the hard disk. This method is only recommended for special
cases when no other installation method is available.

2.4.5

Un*x or GNU system

If you are running another Unix-like system, you could use it to install Debian GNU/Linux without using the debian-installer
described in the rest of this manual. This kind of install may be useful for users with otherwise unsupported hardware or on hosts which can’t afford downtime. If you are interested in this technique, skip to the Section D.3. Thisinstallation method is only recommended for advanced users when no other installation method is available.

2.4.6

Supported Storage Systems

The Debian installer contains a kernel which is built to maximize the number of systems it runs on.
IDE systems are also supported.

2.5

Memory and Disk Space Requirements

You must have at least 260MB of memory and 1160MB of hard disk space to perform a normal installation. Notethat these are fairly minimal numbers. For more realistic figures, see Section 3.4.
The installer normally automatically enables memory-saving tricks to be able to run on such low-memory system,
but on architectures that are less tested it may miss doing so. It can however be enabled manually by appending thelowmem=1 or even lowmem=2 boot parameter (see also Section 6.3.1.1 and Section 5.3.2).
Installation on systems with less memory¹ or disk space available may be possible but is only advised for experienced users.

¹Installation images that support the graphical installer require more memory than images that support only the text-based installer and should
not be used on systems with less than 260MB of memory. If there is a choice between booting the text-based and the graphical installer, the former
should be selected on such systems.

9Chapter 3

Before Installing Debian GNU/LinuxThis chapter deals with the preparation for installing Debian before you even boot the installer. This includes backing
up your data, gathering information about your hardware, and locating any necessary information.

3.1

Overview of the Installation Process

First, just a note about re-installations. With Debian, a circumstance that will require a complete re-installation ofyour system is very rare; perhaps mechanical failure of the hard disk would be the most common case.
Many common operating systems may require a complete installation to be performed when critical failures takeplace or for upgrades to new OS versions. Even if a completely new installation isn’t required, often the programs you
use must be re-installed to operate properly in the new OS.
Under Debian GNU/Linux, it is much more likely that your OS can be repaired rather than replaced if things
go wrong. Upgrades never require a wholesale installation; you can always upgrade in-place. And the programs arealmost always compatible with successive OS releases. If a new program version requires newer supporting software,
the Debian packaging system ensures that all the necessary software is automatically identified and installed. The
point is, much effort has been put into avoiding the need for re-installation, so think of it as your very last option. The
installer is not designed to re-install over an existing system.
Here’s a road map for the steps you will take during the installation process.
1. Back up any existing data or documents on the hard disk where you plan to install.
2. Gather information about your computer and any needed documentation, before starting the installation.
3. Create partitionable space for Debian on your hard disk.
4. Locate and/or download the installer software and any specialized driver or firmware files your machine requires.
5. Set up boot media such as CDs/DVDs/USB sticks or provide a network boot infrastructure from which the
installer can be booted.
6. Boot the installation system.
7. Select the installation language.
8. Activate the ethernet network connection, if available.
9. Create and mount the partitions on which Debian will be installed.
10. Watch the automatic download/install/setup of the base system.
11. Select and install additional software.
12. Install a boot loader which can start up Debian GNU/Linux and/or your existing system.
13. Load the newly installed system for the first time.

10

CHAPTER 3. BEFORE INSTALLING DEBIAN …

3.2. BACK UP YOUR EXISTING DATA!

For 64-bit ARM you have the option of using an experimental graphical version of the installation system. For
more information about this graphical installer, see Section 5.1.6.
If you have problems during the installation, it helps to know which packages are involved in which steps. Introducing the leading software actors in this installation drama:
The installer software, debian-installer, is the primary concern of this manual. It detects hardware andloads appropriate drivers, uses dhcp-client to set up the network connection, runs debootstrap to install thebase system packages, and runs tasksel to allow you to install certain additional software. Many more actors playsmaller parts in this process, but debian-installer has completed its task when you load the new system forthe first time.
To tune the system to your needs, tasksel allows you to choose to install various predefined bundles of software
like a Web server or a Desktop environment.
One important option during the installation is whether or not to install a graphical desktop environment, consistingof the X Window System and one of the available graphical desktop environments. If you choose not to select the“Desktop environment” task, you will only have a relatively basic, command line driven system. Installing the Desktop
environment task is optional because in relation to a text-mode-only system it requires a comparatively large amount of
disk space and because many Debian GNU/Linux systems are servers which don’t really have any need for a graphicaluser interface to do their job.
Just be aware that the X Window System is completely separate from debian-installer, and in fact is much
more complicated. Troubleshooting of the X Window System is not within the scope of this manual.

3.2

Back Up Your Existing Data!

Before you start, make sure to back up every file that is now on your system. If this is the first time a non-native
operating system is going to be installed on your computer, it is quite likely you will need to re-partition your disk
to make room for Debian GNU/Linux. Anytime you partition your disk, you run a risk of losing everything on thedisk, no matter what program you use to do it. The programs used in the installation of Debian GNU/Linux arequite reliable and most have seen years of use; but they are also quite powerful and a false move can cost you. Even
after backing up, be careful and think about your answers and actions. Two minutes of thinking can save hours of
unnecessary work.
If you are creating a multi-boot system, make sure that you have the distribution media of any other present
operating systems on hand. Even though this is normally not necessary, there might be situations in which you could
be required to reinstall your operating system’s boot loader to make the system boot or in a worst case even have toreinstall the complete operating system and restore your previously made backup.

3.3

Information You Will Need3.3.1

Documentation

3.3.1.1

Installation Manual

The document you are now reading, which is the official version of the Installation Guide for the bookworm releaseof Debian; available in various formats and translations.
3.3.1.2

Hardware documentation

Often contains useful information on configuring or using your hardware.

3.3.2

Finding Sources of Hardware Information

In many cases, the installer will be able to automatically detect your hardware. But to be prepared, we do recommend
familiarizing yourself with your hardware before the install.
Hardware information can be gathered from:• The manuals that come with each piece of hardware.
• The BIOS/UEFI setup screens of your computer. You can view these screens when you start your computer bypressing a combination of keys. Check your manual for the combination. Often, it is the Delete or the F2 key,
but some manufacturers use other keys or key combinations. Usually upon starting the computer there will bea message stating which key to press to enter the setup screen.
11

CHAPTER 3. BEFORE INSTALLING DEBIAN …

3.3. INFORMATION YOU WILL NEED• The cases and boxes for each piece of hardware.
• System commands or tools in another operating system, including file manager displays. This source is especially
useful for information about RAM and hard drive memory.
• Your system administrator or Internet Service Provider. These sources can tell you the settings you need to set
up your networking and e-mail.
Table 3.1 Hardware Information Helpful for an Install
HardwareInformation You Might Need
How many you have.
Their order on the system.
Whether IDE (also known as PATA), SATA or SCSI.
Available free space.
Partitions.
Partitions where other operating systems are installed.
Type/model of available network interfaces.
Model and manufacturer.
Type/model and manufacturer.

Hard Drives

Network interfaces
PrinterVideo Card

3.3.3

Hardware Compatibility

Many products work without trouble on Linux. Moreover, hardware support in Linux is improving daily. However,Linux still does not run as many different types of hardware as some operating systems.
Drivers in Linux in most cases are not written for a certain “product” or “brand” from a specific manufacturer,
but for a certain hardware/chipset. Many seemingly different products/brands are based on the same hardware design;
it is not uncommon that chip manufacturers provide so-called “reference designs” for products based on their chips
which are then used by several different device manufacturers and sold under lots of different product or brand names.
This has advantages and disadvantages. An advantage is that a driver for one chipset works with lots of different
products from different manufacturers, as long as their product is based on the same chipset. The disadvantage is that
it is not always easy to see which actual chipset is used in a certain product/brand. Unfortunately sometimes device
manufacturers change the hardware base of their product without changing the product name or at least the productversion number, so that when having two items of the same brand/product name bought at different times, they cansometimes be based on two different chipsets and therefore use two different drivers or there might be no driver at allfor one of them.
For USB and PCI/PCI-Express/ExpressCard devices, a good way to find out on which chipset they are based is tolook at their device IDs. All USB/PCI/PCI-Express/ExpressCard devices have so called “vendor” and “product” IDs,and the combination of these two is usually the same for any product based on the same chipset.
On Linux systems, these IDs can be read with the lsusb command for USB devices and with the lspci -nn command for PCI/PCI-Express/ExpressCard devices. The vendor and product IDs are usually given in the form of two
hexadecimal numbers, separated by a colon, such as “1d6b:0001”.
An example for the output of lsusb: “Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub”,
whereby 1d6b is the vendor ID and 0002 is the product ID.
An example for the output of lspci -nn for an Ethernet card: “03:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller [10ec:8168] (rev 06)”. The IDs are
given inside the rightmost square brackets, i.e. here 10ec is the vendor- and 8168 is the product ID.
As another example, a graphics card could give the following output: “04:00.0 VGA compatible controller [0300]:
Advanced Micro Devices [AMD] nee ATI RV710 [Radeon HD 4350] [1002:954f]”.
On Windows systems, the IDs for a device can be found in the Windows device manager on the tab “details”,
where the vendor ID is prefixed with VEN_ and the product ID is prefixed with DEV_. On Windows 7 systems, youhave to select the property “Hardware IDs” in the device manager’s details tab to actually see the IDs, as they are notdisplayed by default.
Searching on the internet with the vendor/product ID, “Linux” and “driver” as the search terms often results in information regarding the driver support status for a certain chipset. If a search for the vendor/product ID does not yieldusable results, a search for the chip code names, which are also often provided by lsusb and lspci (“RTL8111”/“RTL8168B”
in the network card example and “RV710” in the graphics card example), can help.

12CHAPTER 3. BEFORE INSTALLING DEBIAN …

3.3.3.1

3.4. MEETING MINIMUM HARDWARE …

Testing hardware compatibility with a Live-System

Debian GNU/Linux is also available as a so-called “live system” for certain architectures. A live system is a preconfigured ready-to-use system in a compressed format that can be booted and used from a read-only medium like a CD
or DVD. Using it by default does not create any permanent changes on your computer. You can change user settingsand install additional programs from within the live system, but all this only happens in the computer’s RAM, i.e. if
you turn off the computer and boot the live system again, everything is reset to its defaults. If you want to see whether
your hardware is supported by Debian GNU/Linux, the easiest way is to run a Debian live system on it and try it out.
There are a few limitations in using a live system. The first is that as all changes you do within the live system mustbe held in your computer’s RAM, this only works on systems with enough RAM to do that, so installing additionallarge software packages may fail due to memory constraints. Another limitation with regards to hardware compatibility
testing is that the official Debian GNU/Linux live system contains only free components, i.e. there are no non-free
firmware files included in it. Such non-free packages can of course be installed manually within the system, but there
is no automatic detection of required firmware files like in the debian-installer, so installation of non-freecomponents must be done manually if needed.
Information about the available variants of the Debian live images can be found at the Debian Live Images website.

3.3.4

Network Settings

If your computer is connected to a fixed network (i.e. an Ethernet or equivalent connection — not a dialup/PPP
connection) which is administered by somebody else, you should ask your network’s system administrator for thisinformation:• Your host name (you may be able to decide this on your own).
• Your domain name.
• Your computer’s IP address.
• The netmask to use with your network.
• The IP address of the default gateway system you should route to, if your network has a gateway.
• The system on your network that you should use as a DNS (Domain Name Service) server.
If the network you are connected to uses DHCP (Dynamic Host Configuration Protocol) for configuring network
settings, you don’t need this information because the DHCP server will provide it directly to your computer during
the installation process.
If you have internet access via DSL or cable modem (i.e. over a cable tv network) and have a router (often provided
preconfigured by your phone or catv provider) which handles your network connectivity, DHCP is usually available
by default.
If you use a WLAN/WiFi network, you should find out:
• The ESSID (“network name”) of your wireless network.
• The WEP or WPA/WPA2 security key to access the network (if applicable).

3.4

Meeting Minimum Hardware Requirements

Once you have gathered information about your computer’s hardware, check that your hardware will let you do thetype of installation that you want to do.
Depending on your needs, you might manage with less than some of the recommended hardware listed in the tablebelow. However, most users risk being frustrated if they ignore these suggestions.
Table 3.2 Recommended Minimum System Requirements
Install TypeNo desktop
With Desktop

RAM (minimum)
256 megabytes
1 gigabytes

RAM (recommended)
512 megabytes
2 gigabytes

Hard Drive
4 gigabytes
10 gigabytes

The minimum values assumes that swap will be enabled and a non-liveCD image is used. The “No desktop” value
assumes that the non-graphical (text-based) installer is used.
13

CHAPTER 3. BEFORE INSTALLING DEBIAN …

3.5. PRE-PARTITIONING FOR MULTI-BOOT SYSTEMSThe actual minimum memory requirements are a lot less than the numbers listed in this table. With swap enabled,
it is possible to install Debian with as little as 245MB. The same goes for the disk space requirements, especially if you
pick and choose which applications to install; see Section D.2 for additional information on disk space requirements.
It is possible to run a graphical desktop environment on older or low-end systems, but in that case it is recommended to install a window manager that is less resource-hungry than those of the GNOME or KDE Plasma desktop
environments; alternatives include xfce4, icewm and wmaker, but there are others to choose from.
It is practically impossible to give general memory or disk space requirements for server installations as those verymuch depend on what the server is to be used for.
Remember that these sizes don’t include all the other materials which are usually to be found, such as user files,
mail, and data. It is always best to be generous when considering the space for your own files and data.
Disk space required for the smooth operation of the Debian GNU/Linux system itself is taken into account inthese recommended system requirements. Notably, the /var partition contains a lot of state information specific to
Debian in addition to its regular contents, like logfiles. The dpkg files (with information on all installed packages)
can easily consume 40MB. Also, apt puts downloaded packages here before they are installed. You should usually
allocate at least 200MB for /var, and a lot more if you install a graphical desktop environment.

3.5

Pre-Partitioning for Multi-Boot Systems

Partitioning your disk simply refers to the act of breaking up your disk into sections. Each section is then independentof the others. It’s roughly equivalent to putting up walls inside a house; if you add furniture to one room it doesn’t
affect any other room.
If you already have an operating system on your system which uses the whole disk and you want to stick Debianon the same disk, you will need to repartition it. Debian requires its own hard disk partitions. It cannot be installedon Windows or Mac OS X partitions. It may be able to share some partitions with other Unix systems, but that’s notcovered here. At the very least you will need a dedicated partition for the Debian root filesystem.
You can find information about your current partition setup by using a partitioning tool for your current operating
system. Partitioning tools always provide a way to show existing partitions without making changes.
In general, changing a partition with a file system already on it will destroy any information there. Thus you should
always make backups before doing any repartitioning. Using the analogy of the house, you would probably want tomove all the furniture out of the way before moving a wall or you risk destroying it.
Several modern operating systems offer the ability to move and resize certain existing partitions without destroying
their contents. This allows making space for additional partitions without losing existing data. Even though this works
quite well in most cases, making changes to the partitioning of a disk is an inherently dangerous action and should
only be done after having made a full backup of all data.

3.6

Pre-Installation Hardware and Operating System Setup

This section will walk you through pre-installation hardware setup, if any, that you will need to do prior to installing
Debian. Generally, this involves checking and possibly changing BIOS/UEFI/system firmware settings for your system. The “BIOS/UEFI” or “system firmware” is the core software used by the hardware; it is most critically invoked
during the bootstrap process (after power-up).

3.6.1

Boot Device Selection

3.6.2

ARM firmware

As already mentioned before, there is unfortunately no standard for system firmware on ARM systems. Even the
behaviour of different systems which use nominally the same firmware can be quite different. This results from the factthat a large part of the devices using the ARM architecture are embedded systems, for which the manufacturers usuallybuild heavily customized firmware versions and include device-specific patches. Unfortunately the manufacturers
often do not submit their changes and extensions back to the mainline firmware developers, so their changes are notintegrated into newer versions of the original firmware.
As a result even newly sold systems often use a firmware that is based on a years-old manufacturer-modified version
of a firmware whose mainline codebase has evolved a lot further in the meantime and offers additional features orshows different behaviour in certain aspects. In addition to that, the naming of onboard devices is not consistent
between different manufacturer-modified versions of the same firmware, therefore it is nearly impossible to provide
usable product-independend instructions for ARM-based systems.

14

CHAPTER 3. BEFORE INSTALLING DEBIAN …

3.6.3

3.6. PRE-INSTALLATION HARDWARE AND …

Setting the ethernet MAC address in U-Boot

The MAC address of every ethernet interface should normally be globally unique, and it technically has to be unique
within its ethernet broadcast domain. To achieve this, the manufacturer usually allocates a block of MAC addresses
from a centrally-administered pool (for which a fee has to be paid) and preconfigures one of these addresses on each
item sold.
In the case of development boards, sometimes the manufacturer wants to avoid paying these fees and therefore
provides no globally unique addresses. In these cases the users themselves have to define MAC addresses for theirsystems. When no MAC address is defined for an ethernet interface, some network drivers generate a random MAC
address that can change on every boot, and if this happens, network access would be possible even when the user has
not manually set an address, but e.g. assigning semi-static IP addresses by DHCP based on the MAC address of therequesting client would obviously not work reliably.
To avoid conflicts with existing officially-assigned MAC addresses, there is an address pool which is reserved for
so-called “locally administered” addresses. It is defined by the value of two specific bits in the first byte of the address(the article “MAC address” in the English language Wikipedia gives a good explanation). In practice this means thate.g. any address starting with hexadecimal ca (such as ca:ff:ee:12:34:56) can be used as a locally administered address.
On systems using U-Boot as system firmware, the ethernet MAC address is placed in the “ethaddr” environment
variable. It can be checked at the U-Boot command prompt with the command “printenv ethaddr” and can be set
with the command “setenv ethaddr ca:ff:ee:12:34:56”. After setting the value, the command “saveenv” makes theassignment permanent.

3.6.4

Kernel/Initrd/Device-Tree relocation issues in U-Boot

On some systems with older U-Boot versions there can be problems with properly relocating the Linux kernel, theinitial ramdisk and the device-tree blob in memory during the boot process. In this case, U-Boot shows the message“Starting kernel ...”, but the system freezes afterwards without further output. These issues have been solved withnewer U-Boot versions from v2014.07 onwards.
If the system has originally used a U-Boot version older than v2014.07 and has been upgraded to a newer version
later, the problem might still occur even after upgrading U-Boot. Upgrading U-Boot usually does not modify theexisting U-Boot environment variables and the fix requires an additional environment variable (bootm_size) to be
set, which U-Boot does automatically only on fresh installations without existing environment data. It is possible
to manually set bootm_size to the new U-Boot’s default value by running the command “env default bootm_size;
saveenv” at the U-Boot prompt.
Another possibility to circumvent relocation-related problems is to run the command “setenv fdt_high ffffffff;
setenv initrd_high 0xffffffff; saveenv” at the U-Boot prompt to completely disable the relocation of the initial ramdisk
and the device-tree blob.

15

Chapter 4

Obtaining System Installation Media
4.1

Official Debian GNU/Linux installation images

By far the easiest way to install Debian GNU/Linux is from a set of official Debian installation images. You can
buy a set of CDs/DVDs from a vendor (see the CD vendors page). You may also download the installation images
from a Debian mirror and make your own set, if you have a fast network connection and a CD/DVD burner (see the
Debian CD/DVD page and Debian CD FAQ for detailed instructions). If you have such optical installation media,
and they are bootable on your machine, you can skip right to Chapter 5. Much effort has been expended to ensure themost-used files are on the first CD and DVD image, so that a basic desktop installation can be done with only the first
DVD or - to a limited extent - even with only the first CD image.
As CDs have a rather limited capacity by today’s standards, not all graphical desktop environments are installable
with only the first CD; for some desktop environments a CD installation requires either network connectivity during
the installation to download the remaining files or additional CDs.
Also, keep in mind: if the installation media you are using don’t contain some packages you need, you can always
install those packages afterwards from your running new Debian system (after the installation has finished). If you
need to know on which installation image to find a specific package, visit https://cdimage-search.debian.org/.
If your machine doesn’t support booting from optical media, but you do have a set of CD/DVD, you can use analternative strategy such as usb stick, net boot, or manually loading the kernel from the disc to initially boot the systeminstaller. The files you need for booting by another means are also on the disc; the Debian network archive and folder
organization on the disc are identical. So when archive file paths are given below for particular files you need forbooting, look for those files in the same directories and subdirectories on your installation media.
Once the installer is booted, it will be able to obtain all the other files it needs from the disc.
If you don’t have an installation media set, then you will need to download the installer system files and place themon the usb stick or a connected computer so they can be used to boot the installer.

4.2

Downloading Files from Debian Mirrors

To find the nearest (and thus probably the fastest) mirror, see the list of Debian mirrors.

4.2.1

Where to Find Installation Files

Various installation files can be found on each Debian mirror in the directory debian/dists/bookworm/main/installerarm64/current/images/ — the MANIFEST lists each image and its purpose.

4.3

Preparing Files for USB Memory Stick Booting

To prepare the USB stick, we recommend to use a system where GNU/Linux is already running and where USB is
supported. With current GNU/Linux systems the USB stick should be automatically recognized when you insert it.
If it is not you should check that the usb-storage kernel module is loaded. When the USB stick is inserted, it will bemapped to a device named /dev/sdX, where the “X” is a letter in the range a-z. You should be able to see to which
device the USB stick was mapped by running the command lsblk before and after inserting it. (The output of dmesg(as root) is another possible method for that.) To write to your stick, you may have to turn off its write protection
switch.

16

CHAPTER 4. OBTAINING SYSTEM INSTALLATION …

4.4. PREPARING FILES FOR TFTP NET BOOTINGWARNING
The procedures described in this section will destroy anything already on the device! Make very sure that you use the correct device name for your USB stick. If
you use the wrong device the result could be that all information on, for example, a
hard disk is lost.

4.3.1

Preparing a USB stick using a hybrid CD/DVD image

Debian installation images for this architecture are created using the isohybrid technology; that means they can be
written directly to a USB stick, which is a very easy way to make an installation media. Simply choose an image (suchas the netinst, CD or DVD-1) that will fit on your USB stick. See Section 4.1 to get an installation image.
The installation image you choose should be written directly to the USB stick, overwriting its current contents.
For example, when using an existing GNU/Linux system, the image file can be written to a USB stick as follows, after
having made sure that the stick is unmounted:# cp debian.iso /dev/sdX# syncSimply writing the installation image to USB like this should work fine for most users. For special needs there is thiswiki page.
Information about how to do this on other operating systems can be found in the Debian CD FAQ.

IMPORTANTThe image must be written to the whole-disk device and not a partition, e.g. /dev/sdb and not /dev/sdb1. Do not use tools like unetbootin which alter the image.

4.4

Preparing Files for TFTP Net Booting

If your machine is connected to a local area network, you may be able to boot it over the network from anothermachine, using TFTP. If you intend to boot the installation system from another machine, the boot files will need
to be placed in specific locations on that machine, and the machine configured to support booting of your specificmachine.
You need to set up a TFTP server, and for many machines a DHCP server, or RARP server, or BOOTP server.
The Reverse Address Resolution Protocol (RARP) is one way to tell your client what IP address to use for itself.
Another way is to use the BOOTP protocol. BOOTP is an IP protocol that informs a computer of its IP address andwhere on the network to obtain a boot image. The DHCP (Dynamic Host Configuration Protocol) is a more flexible,
backwards-compatible extension of BOOTP. Some systems can only be configured via DHCP.
The Trivial File Transfer Protocol (TFTP) is used to serve the boot image to the client. Theoretically, any server,
on any platform, which implements these protocols, may be used. In the examples in this section, we shall provide
commands for SunOS 4.x, SunOS 5.x (a.k.a. Solaris), and GNU/Linux.

4.4.1

Setting up RARP server

To set up RARP, you need to know the Ethernet address (a.k.a. the MAC address) of the client computers to beinstalled. If you don’t know this information, you can boot into “Rescue” mode and use the command ip addr
show dev eth0.
On a RARP server system using a Linux kernel or Solaris/SunOS, you use the rarpd program. You need to ensurethat the Ethernet hardware address for the client is listed in the “ethers” database (either in the /etc/ethers file,or via NIS/NIS+) and in the “hosts” database. Then you need to start the RARP daemon. Issue the command (as17

CHAPTER 4. OBTAINING SYSTEM INSTALLATION …

4.4. PREPARING FILES FOR TFTP NET BOOTINGroot): /usr/sbin/rarpd -a on most Linux systems and SunOS 5 (Solaris 2), /usr/sbin/in.rarpd -a
on some other Linux systems, or /usr/etc/rarpd -a in SunOS 4 (Solaris 1).

4.4.2

Setting up a DHCP server

One free software DHCP server is ISC dhcpd. For Debian GNU/Linux, the isc-dhcp-server package is recommended. Here is a sample configuration file for it (see /etc/dhcp/dhcpd.conf):
option domain-name ”example.com”;
option domain-name-servers ns1.example.com;
option subnet-mask 255.255.255.0;
default-lease-time 600;
max-lease-time 7200;
server-name ”servername”;
subnet 192.168.1.0 netmask 255.255.255.0 {range 192.168.1.200 192.168.1.253;
option routers 192.168.1.1;}
host clientname {filename ”/tftpboot.img”;
server-name ”servername”;
next-server servername;hardware ethernet 01:23:45:67:89:AB;
fixed-address 192.168.1.90;}

In this example, there is one server servername which performs all of the work of DHCP server, TFTP server,
and network gateway. You will almost certainly need to change the domain-name options, as well as the server nameand client hardware address. The filename option should be the name of the file which will be retrieved via TFTP.
After you have edited the dhcpd configuration file, restart it with /etc/init.d/isc-dhcp-server restart.

4.4.3

Setting up a BOOTP server

There are two BOOTP servers available for GNU/Linux. The first is CMU bootpd. The other is actually a DHCP
server: ISC dhcpd. In Debian GNU/Linux these are contained in the bootp and isc-dhcp-server packages
respectively.
To use CMU bootpd, you must first uncomment (or add) the relevant line in /etc/inetd.conf. On Debian
GNU/Linux, you can run update-inetd --enable bootps, then /etc/init.d/inetd reload todo so. Just in case your BOOTP server does not run Debian, the line in question should look like:bootps

dgram

udp

wait

root

/usr/sbin/bootpd

bootpd -i -t 120

Now, you must create an /etc/bootptab file. This has the same sort of familiar and cryptic format as the good old
BSD printcap, termcap, and disktab files. See the bootptab manual page for more information. For CMU
bootpd, you will need to know the hardware (MAC) address of the client. Here is an example /etc/bootptab:
client:\hd=/tftpboot:\bf=tftpboot.img:\
ip=192.168.1.90:\
sm=255.255.255.0:\
sa=192.168.1.1:\
ha=0123456789AB:

You will need to change at least the “ha” option, which specifies the hardware address of the client. The “bf” option
specifies the file a client should retrieve via TFTP; see Section 4.4.5 for more details.
By contrast, setting up BOOTP with ISC dhcpd is really easy, because it treats BOOTP clients as a moderately
special case of DHCP clients. Some architectures require a complex configuration for booting clients via BOOTP.
If yours is one of those, read the section Section 4.4.2. Otherwise you will probably be able to get away with simply
adding the allow bootp directive to the configuration block for the subnet containing the client in /etc/dhcp/
dhcpd.conf, and restart dhcpd with /etc/init.d/isc-dhcp-server restart.

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CHAPTER 4. OBTAINING SYSTEM INSTALLATION …

4.4.4

4.5. AUTOMATIC INSTALLATION

Enabling the TFTP Server

To get the TFTP server ready to go, you should first make sure that tftpd is enabled.
In the case of tftpd-hpa there are two ways the service can be run. It can be started on demand by the system’s
inetd daemon, or it can be set up to run as an independent daemon. Which of these methods is used is selected
when the package is installed and can be changed by reconfiguring the package.

NOTEHistorically, TFTP servers used /tftpboot as directory to serve images from.
However, Debian GNU/Linux packages may use other directories to comply with
the Filesystem Hierarchy Standard. For example, tftpd-hpa by default uses
/srv/tftp. You may have to adjust the configuration examples in this section
accordingly.
All in.tftpd alternatives available in Debian should log TFTP requests to the system logs by default. Some ofthem support a -v argument to increase verbosity. It is recommended to check these log messages in case of bootproblems as they are a good starting point for diagnosing the cause of errors.

4.4.5

Move TFTP Images Into Place

Next, place the TFTP boot image you need, as found in Section 4.2.1, in the tftpd boot image directory. You may
have to make a link from that file to the file which tftpd will use for booting a particular client. Unfortunately, the filename is determined by the TFTP client, and there are no strong standards.

4.5

Automatic Installation

For installing on multiple computers it’s possible to do fully automatic installations. Debian packages intended for thisinclude fai-quickstart (which can use an install server) and the Debian Installer itself. Have a look at the FAI
home page for detailed information.

4.5.1

Automatic Installation Using the Debian Installer

The Debian Installer supports automating installs via preconfiguration files. A preconfiguration file can be loaded fromthe network or from removable media, and used to fill in answers to questions asked during the installation process.
Full documentation on preseeding including a working example that you can edit is in Appendix B.

4.6

Verifying the integrity of installation files

You can verify the integrity of downloaded files against checksums provided in SHA256SUMS or SHA512SUMS
files on Debian mirrors. You can find them in the same places as the installation images itself. Visit the following
locations:• checksum files for CD images,• checksum files for DVD images,• checksum files for other installation files.
To compute the checksum of a downloaded installation file, use
sha256sum filename.isorespective
sha512sum filename.iso19

CHAPTER 4. OBTAINING SYSTEM INSTALLATION …

4.6. VERIFYING THE INTEGRITY OF …

and then compare the shown checksum against the corresponding one in the SHA256SUMS respective SHA512SUMS
file.
The Debian CD FAQ has more useful information on this topic (such as the script check_debian_iso, tosemi-automate above procedure), as well as instructions, how to verify the integrity of the above checksum files
themselves.

20

Chapter 5

Booting the Installation System
5.1

Booting the Installer on 64-bit ARM

NOTEFor information on how to boot the graphical installer, see Section 5.1.6.

5.1.1

Console configuration

The graphical installer is (experimentally) enabled on the arm64 debian-installer images, but on some devices
you may still have to use the serial console. The console device should be detected automatically from the firmware,
but if it is not then after you boot linux from the GRUB menu you will see a “Booting Linux” message, then nothing
more.
If you hit this issue you will need to set a specific console config on the kernel command line. Hit e for “Edit
Kernel command-line” at the GRUB menu, and change--- quiet

toconsole=<device>,<speed>e.g.
console=ttyAMA0,115200n8. When finished hit Control-x to continue booting with new setting.

5.1.2

Juno Installation

Juno has UEFI so the install is straightforward. The most practical method is installing from USB stick. You need
up to date firmware for USB-booting to work. Builds from http://releases.linaro.org/members/arm/platforms/latest/
after March 2015 tested OK. Consult Juno documentation on firmware updating.
Prepare a standard arm64 CD/DVD image on a USB stick. Insert it in one of the USB ports on the back. Pluga serial cable into the upper 9-pin serial port on the back. If you need networking (netboot image) plug the ethernet
cable into the socket on the front of the machine.
Run a serial console at 115200, 8bit no parity, and boot the Juno. It should boot from the USB stick to a GRUB
menu. The console config is not correctly detected on Juno so just hitting Enter will show no kernel output. Set theconsole toconsole=ttyAMA0,115200n8(as described in Section 5.1.1). Control-x to boot should show you the debian-installer screens, and allow
you to proceed with a standard installation.
21

CHAPTER 5. BOOTING THE INSTALLATION SYSTEM

5.1.3

5.1. BOOTING THE INSTALLER ON 64-BIT ARM

Applied Micro Mustang Installation

UEFI is available for this machine but it is normally shipped with U-Boot so you will need to either install UEFI
firmware first then use standard boot/install methods, or use U-Boot boot methods. You must use a serial console tocontrol the installation because the graphical installer is not enabled on the arm64 architecture.
The recommended install method is to copy the debian-installer kernel and initrd onto the hard drive,
using the openembedded system supplied with the machine, then boot from that to run the installer. Alternatively use
TFTP to get the kernel/dtb/initrd copied over and booted (Section 5.1.4.1). After installation, manual changes to bootfrom the installed image are needed.
Run a serial console at 115200, 8bit no parity, and boot the machine. Reboot the machine and when you see “Hitany key to stop autoboot:” hit a key to get a Mustang# prompt. Then use U-Boot commands to load and boot thekernel, dtb and initrd.

5.1.4

Booting by TFTP

Booting from the network requires that you have a network connection and a TFTP network boot server (and probably
also a DHCP, RARP, or BOOTP server for automatic network configuration).
The server-side setup to support network booting is described in Section 4.4.
5.1.4.1

TFTP-booting in U-Boot

Network booting on systems using the U-Boot firmware consists of three steps: a) configuring the network, b) loading
the images (kernel/initial ramdisk/dtb) into memory and c) actually executing the previosly loaded code.
First you have to configure the network, either automatically via DHCP by runningsetenv autoload nodhcp

or manually by setting several environment variables
setenv ipaddr <ip address of the client>setenv netmask <netmask>setenv serverip <ip address of the tftp server>
setenv dnsip <ip address of the nameserver>
setenv gatewayip <ip address of the default gateway>

If you prefer, you can make these settings permanent by runningsaveenv

Afterwards you need to load the images (kernel/initial ramdisk/dtb) into memory. This is done with the tftpboot
command, which has to be provided with the address at which the image shall be stored in memory. Unfortunately
the memory map can vary from system to system, so there is no general rule which addresses can be used for this.
On some systems, U-Boot predefines a set of environment variables with suitable load addresses: kernel_addr_r,
ramdisk_addr_r and fdt_addr_r. You can check whether they are defined by running
printenv kernel_addr_r ramdisk_addr_r fdt_addr_r

If they are not defined, you have to check your system’s documentation for appropriate values and set them manually.
For systems based on Allwinner SunXi SOCs (e.g. the Allwinner A10, architecture name “sun4i” or the Allwinner
A20, architecture name “sun7i”), you can e.g. use the following values:
setenv kernel_addr_r 0x46000000
setenv fdt_addr_r 0x47000000
setenv ramdisk_addr_r 0x48000000

When the load addresses are defined, you can load the images into memory from the previously defined tftp server
with
tftpboot ${kernel_addr_r} <filename of the kernel image>tftpboot ${fdt_addr_r} <filename of the dtb>
tftpboot ${ramdisk_addr_r} <filename of the initial ramdisk image>22

CHAPTER 5. BOOTING THE INSTALLATION SYSTEM

5.2. ACCESSIBILITY

The third part is setting the kernel commandline and actually executing the loaded code. U-Boot passes the content
of the “bootargs” environment variable as commandline to the kernel, so any parameters for the kernel and the installer- such as the console device (see Section 5.3.1) or preseeding options (see Section 5.3.2 and Appendix B) - can be set
with a command likesetenv bootargs console=ttyS0,115200 rootwait panic=10

The exact command to execute the previously loaded code depends on the image format used. With uImage/uInitrd,
the command isbootm ${kernel_addr_r} ${ramdisk_addr_r} ${fdt_addr_r}

and with native Linux images it isbootz ${kernel_addr_r} ${ramdisk_addr_r}:${filesize} ${fdt_addr_r}

Note: When booting standard linux images, it is important to load the initial ramdisk image after the kernel andthe dtb as U-Boot sets the filesize variable to the size of the last file loaded and the bootz command requires the size ofthe ramdisk image to work correctly. In case of booting a platform-specific kernel, i.e. a kernel without device-tree,
simply omit the ${fdt_addr_r} parameter.

5.1.5

Booting from USB Memory Stick with UEFI

If your computer will boot from USB, this will probably be the easiest route for installation. Assuming you have
prepared everything from Section 3.6.1 and Section 4.3, just plug your USB stick into some free USB connector andreboot the computer. The system should boot up, and unless you have used the flexible way to build the stick and notenabled it, you should be presented with a graphical boot menu (on hardware that supports it). Here you can selectvarious installer options, or just hit Enter.

5.1.6

The Graphical Installer

The graphical version of the installer is only available for a limited number of architectures, including 64-bit ARM.
The functionality of the graphical installer is essentially the same as that of the text-based installer as it basically uses
the same programs, but with a different frontend.
Although the functionality is identical, the graphical installer still has a few significant advantages. The main
advantage is that it supports more languages, namely those that use a character set that cannot be displayed with thetext-based “newt” frontend. It also has a few usability advantages such as the option to use a mouse, and in some cases
several questions can be displayed on a single screen.
Just as with the text-based installer it is possible to add boot parameters when starting the graphical installer.

NOTE
The graphical installer requires significantly more memory to run than the text-based
installer: 640MB. If insufficient memory is available, it will automatically fall back to
the text-based “newt” frontend.
If the amount of memory in your system is below 260MB, the graphical installer may
fail to boot at all while booting the text-based installer would still work. Using thetext-based installer is recommended for systems with little available memory.

5.2

Accessibility

Some users may need specific support because of e.g. some visual impairment. Most accessibility features have to
be enabled manually. Some boot parameters can be appended to enable accessibility features. Note that on mostarchitectures the boot loader interprets your keyboard as a QWERTY keyboard.

23

CHAPTER 5. BOOTING THE INSTALLATION SYSTEM

5.2.1

5.3. BOOT PARAMETERS

Installer front-end

The Debian installer supports several front-ends for asking questions, with varying convenience for accessibility: notably, text uses plain text while newt uses text-based dialog boxes. The choice can be made at the boot prompt,
see the documentation for DEBIAN_FRONTEND in Section 5.3.2.
With the newt front-end (used mostly with braille), one mostly just selects answers with arrow keys and presses
Enter to validate the choice. Pressing Tab or Shift - Tab allows to switch between dialog elements, and notably
to access the Go Back button, which brings back again to previous questions. Some dialogs contain check boxes,
which can be ticked on and off by pressing Space.
With the text front-end (used mostly with speech), one mostly selects answers either by typing their number
followed by pressing Enter, or by selecting an answer with arrow keys, and pressing Enter to validate the choice.
One can also not type anything and just press Enter to simply accept the default value. Typing < and pressing Enter
brings back again to previous questions. When a selection of choices has to be made (e.g. during task selection), one
can type ! to express an empty selection.

5.2.2

Board Devices

Some accessibility devices are actual boards that are plugged inside the machine and that read text directly from thevideo memory. To get them to work framebuffer support must be disabled by using the fb=false boot parameter.
This will however reduce the number of available languages.

5.2.3

High-Contrast ThemeFor users with low vision, the installer can use a high-contrast color theme that makes it more readable. To enable it,
you can use the “Accessible high contrast” entry from the boot screen with the d shortcut, or append the theme=dark
boot parameter.

5.2.4

Zoom

For users with low vision, the graphical installer has a very basic zoom support: the Control-+ and Control– shortcuts
increase and decrease the font size.

5.2.5

Expert install, rescue mode, automated installExpert, Rescue, and Automated installation choices are also available with accessibility support. To access them, one
has to first enter the “Advanced options” submenu from the boot menu by typing a. When using a BIOS system (theboot menu will have beeped only once), this has to be followed by Enter ; for UEFI systems (the boot menu will
have beeped twice) that must not be done. Then, to enable speech synthesis, s can optionally be pressed (followed
again by Enter on BIOS systems but not on UEFI systems). From there, various shortcuts can be used: x for expert
installation, r for rescue mode, or a for automated installation. Again these need to be followed by Enter when using
a BIOS system.
The automated install choice allows to install Debian completely automatically by using preseeding, whose source
can be entered after accessibility features get started. Preseeding itself is documented in Appendix B.

5.2.6

Accessibility of the installed system

Documentation on accessibility of the installed system is available on the Debian Accessibility wiki page.

5.3

Boot Parameters

Boot parameters are Linux kernel parameters which are generally used to make sure that peripherals are dealt withproperly. For the most part, the kernel can auto-detect information about your peripherals. However, in some cases
you’ll have to help the kernel a bit.
If this is the first time you’re booting the system, try the default boot parameters (i.e., don’t try setting parameters)
and see if it works correctly. It probably will. If not, you can reboot later and look for any special parameters that
inform the system about your hardware.
Information on many boot parameters can be found in the Linux BootPrompt HOWTO, including tips for obscure
hardware. This section contains only a sketch of the most salient parameters. Some common gotchas are included
below in Section 5.4.
24

CHAPTER 5. BOOTING THE INSTALLATION SYSTEM

5.3.1

5.3. BOOT PARAMETERS

Boot console

If you are booting with a serial console, generally the kernel will autodetect this. If you have a videocard (framebuffer)and a keyboard also attached to the computer which you wish to boot via serial console, you may have to pass theconsole=device argument to the kernel, where device is a serial device of the target, which is usually something
like ttyS0.
You may need to specify parameters for the serial port, such as speed and parity, for instance console=ttyS0,9600n8;
other typical speeds may be 57600 or 115200. Be sure to specify this option after “---”, so that it is copied into thebootloader configuration for the installed system (if supported by the installer for the bootloader).
In order to ensure the terminal type used by the installer matches your terminal emulator, the parameter TERM=typecan be added. Note that the installer only supports the following terminal types: linux, bterm, ansi, vt102
and dumb. The default for serial console in debian-installer is vt102. If you are using an IPMI console, ora virtualization tool which does not provide conversion into such terminals types itself, e.g. QEMU/KVM, you canstart it inside a screen session. That will indeed perform translation into the screen terminal type, which is very
close to vt102.

5.3.2

Debian Installer Parameters

The installation system recognizes a few additional boot parameters¹ which may be useful.
A number of parameters have a “short form” that helps avoid the limitations of the kernel command line options
and makes entering the parameters easier. If a parameter has a short form, it will be listed in brackets behind the(normal) long form. Examples in this manual will normally use the short form too.
debconf/priority (priority) This parameter sets the lowest priority of messages to be displayed.
The default installation uses priority=high. This means that both high and critical priority messages areshown, but medium and low priority messages are skipped. If problems are encountered, the installer adjusts
the priority as needed.
If you add priority=medium as boot parameter, you will be shown the installation menu and gain more
control over the installation. When priority=low is used, all messages are shown (this is equivalent to theexpert boot method). With priority=critical, the installation system will display only critical messages
and try to do the right thing without fuss.
DEBIAN_FRONTEND This boot parameter controls the type of user interface used for the installer. The current
possible parameter settings are:
• DEBIAN_FRONTEND=noninteractive• DEBIAN_FRONTEND=text• DEBIAN_FRONTEND=newt• DEBIAN_FRONTEND=gtk
The default frontend is DEBIAN_FRONTEND=newt. DEBIAN_FRONTEND=text may be preferable forserial console installs. Some specialized types of install media may only offer a limited selection of frontends,
but the newt and text frontends are available on most default install media. On architectures that support it,
the graphical installer uses the gtk frontend.
BOOT_DEBUG Setting this boot parameter to 2 will cause the installer’s boot process to be verbosely logged.
Setting it to 3 makes debug shells available at strategic points in the boot process. (Exit the shells to continue
the boot process.)
BOOT_DEBUG=0 This is the default.
BOOT_DEBUG=1 More verbose than usual.
BOOT_DEBUG=2 Lots of debugging information.
BOOT_DEBUG=3 Shells are run at various points in the boot process to allow detailed debugging. Exit theshell to continue the boot.
log_host, log_port Causes the installer to send log messages to a remote syslog on the specified host and port as wellas to a local file. If not specified, the port defaults to the standard syslog port 514.
¹With current kernels (2.6.9 or newer) you can use 32 command line options and 32 environment options. If these numbers are exceeded, thekernel will panic. Also there is a limit of 255 characters for the whole kernel command line, everything above this limit may be silently truncated.

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5.3. BOOT PARAMETERS

lowmem Can be used to force the installer to a lowmem level higher than the one the installer sets by default basedon available memory. Possible values are 1 and 2. See also Section 6.3.1.1.
noshell Prevents the installer from offering interactive shells on tty2 and tty3. Useful for unattended installations
where physical security is limited.
debian-installer/framebuffer (fb) Some architectures use the kernel framebuffer to offer installation in a numberof languages. If framebuffer causes a problem on your system you can disable the feature using the parameter
fb=false. Problem symptoms are error messages about bterm or bogl, a blank screen, or a freeze within a
few minutes after starting the install.
debian-installer/theme (theme) A theme determines how the user interface of the installer looks (colors, icons,etc.). Which themes are available may differ per frontend. Currently both the newt and gtk frontend have(apart from the default look) only one additional theme named “dark” theme, which was designed for visually
impaired users. Set this theme by booting with theme=dark (there is also the keyboard shortcut d for this in
the boot menu).
netcfg/disable_autoconfig By default, the debian-installer automatically probes for network configuration
via IPv6 autoconfiguration and DHCP. If the probe succeeds, you won’t have a chance to review and change
the obtained settings. You can get to the manual network setup only in case the automatic configuration fails.
If you have an IPv6 router or a DHCP server on your local network, but want to avoid them because e.g. theygive wrong answers, you can use the parameter netcfg/disable_autoconfig=true to prevent any
automatic configuration of the network (neither v4 nor v6) and to enter the information manually.
hw-detect/start_pcmcia Set to false to prevent starting PCMCIA services, if that causes problems. Some laptops
are well known for this misbehavior.
preseed/url (url) Specify the url to a preconfiguration file to download and use for automating the install. See Section 4.5.
preseed/file (file) Specify the path to a preconfiguration file to load for automating the install. See Section 4.5.
preseed/interactive Set to true to display questions even if they have been preseeded. Can be useful for testingor debugging a preconfiguration file. Note that this will have no effect on parameters that are passed as bootparameters, but for those a special syntax can be used. See Section B.5.2 for details.
auto-install/enable (auto) Delay questions that are normally asked before preseeding is possible until after the network is configured. See Section B.2.3 for details about using this to automate installs.
finish-install/keep-consoles During installations from serial or management console, the regular virtual consoles(VT1 to VT6) are normally disabled in /etc/inittab. Set to true to prevent this.
cdrom-detect/eject By default, before rebooting, debian-installer automatically ejects the optical media
used during the installation. This can be unnecessary if the system does not automatically boot off such media.
In some cases it may even be undesirable, for example if the optical drive cannot reinsert the media itself andthe user is not there to do it manually. Many slot loading, slim-line, and caddy style drives cannot reload media
automatically.
Set to false to disable automatic ejection, and be aware that you may need to ensure that the system does not
automatically boot from the optical drive after the initial installation.
base-installer/install-recommends (recommends) By setting this option to false, the package management system will be configured to not automatically install “Recommends”, both during the installation and for the
installed system. See also Section 6.3.5.
Note that this option allows to have a leaner system, but can also result in features being missing that you might
normally expect to be available. You may have to manually install some of the recommended packages to obtainthe full functionality you want. This option should therefore only be used by very experienced users.
debian-installer/allow_unauthenticated By default the installer requires that repositories be authenticated using aknown gpg key. Set to true to disable that authentication. Warning: insecure, not recommended.
rescue/enable Set to true to enter rescue mode rather than performing a normal installation. See Section 8.6.

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5.3.3

5.3. BOOT PARAMETERS

Using boot parameters to answer questions

With some exceptions, a value can be set at the boot prompt for any question asked during the installation, though
this is only really useful in specific cases. General instructions how to do this can be found in Section B.2.2. Some
specific examples are listed below.
debian-installer/language (language), debian-installer/country (country), debian-installer/locale (locale) There
are two ways to specify the language, country and locale to use for the installation and the installed system.
The first and easiest is to pass only the parameter locale. Language and country will then be derived fromits value. You can for example use locale=de_CH to select German as language and Switzerland as country (de_CH.UTF-8 will be set as default locale for the installed system). Limitation is that not all possiblecombinations of language, country and locale can be achieved this way.
The second, more flexible option is to specify language and country separately. In this case locale
can optionally be added to specify a specific default locale for the installed system. Example: language=en
country=DE locale=en_GB.UTF-8.
anna/choose_modules (modules) Can be used to automatically load installer components that are not loaded bydefault. Examples of optional components that may be useful are openssh-client-udeb (so you can use
scp during the installation) and ppp-udeb (see Section D.4).
netcfg/disable_autoconfig Set to true if you want to disable IPv6 autoconfiguration and DHCP and instead force
static network configuration.
mirror/protocol (protocol) By default the installer will use the http protocol to download files from Debian mirrors
and changing that to ftp is not possible during installations at normal priority. By setting this parameter to ftp,
you can force the installer to use that protocol instead. Note that you cannot select an ftp mirror from a list,
you have to enter the hostname manually.
tasksel:tasksel/first (tasks) Can be used to select tasks that are not available from the interactive task list, such as
the kde-desktop task. See Section 6.3.6.2 for additional information.

5.3.4

Passing parameters to kernel modules

If drivers are compiled into the kernel, you can pass parameters to them as described in the kernel documentation.
However, if drivers are compiled as modules and because kernel modules are loaded a bit differently during an installation than when booting an installed system, it is not possible to pass parameters to modules as you would normallydo. Instead, you need to use a special syntax recognized by the installer which will then make sure that the parameters
are saved in the proper configuration files and will thus be used when the modules are actually loaded. The parameters
will also be propagated automatically to the configuration for the installed system.
Note that it is now quite rare that parameters need to be passed to modules. In most cases the kernel will be able
to probe the hardware present in a system and set good defaults that way. However, in some situations it may still beneeded to set parameters manually.
The syntax to use to set parameters for modules is:module_name.parameter_name=value

If you need to pass multiple parameters to the same or different modules, just repeat this. For example, to set an old
3Com network interface card to use the BNC (coax) connector and IRQ 10, you would pass:
3c509.xcvr=3 3c509.irq=10

5.3.5Blacklisting kernel modules

Sometimes it may be necessary to blacklist a module to prevent it from being loaded automatically by the kernel andudev. One reason could be that a particular module causes problems with your hardware. The kernel also sometimes
lists two different drivers for the same device. This can cause the device to not work correctly if the drivers conflict
or if the wrong driver is loaded first.
You can blacklist a module using the following syntax: module_name.blacklist=yes. This will cause themodule to be blacklisted in /etc/modprobe.d/blacklist.local both during the installation and for the
installed system.
Note that a module may still be loaded by the installation system itself. You can prevent that from happening
by running the installation in expert mode and unselecting the module from the list of modules displayed during the
hardware detection phases.
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5.4. TROUBLESHOOTING THE INSTALLATION …

5.4

Troubleshooting the Installation Process

5.4.1

Reliability of optical media

Sometimes, especially with older drives, the installer may fail to boot from an optical disc. The installer may also
— even after booting successfully from such disc — fail to recognize the disc or return errors while reading from it
during the installation.
There are many different possible causes for these problems. We can only list some common issues and provide
general suggestions on how to deal with them. The rest is up to you.
There are two very simple things that you should try first.
• If the disc does not boot, check that it was inserted correctly and that it is not dirty.
• If the installer fails to recognize the disc, try just running the option Detect and mount installation media asecond time. Some DMA related issues with very old CD-ROM drives are known to be resolved in this way.
If this does not work, then try the suggestions in the subsections below. Most, but not all, suggestions discussed
there are valid for CD-ROM and DVD.
If you cannot get the installation working from optical disc, try one of the other installation methods that areavailable.
5.4.1.1

Common issues• Some older CD-ROM drives do not support reading from discs that were burned at high speeds using a modern
CD writer.
• Some very old CD-ROM drives do not work correctly if “direct memory access” (DMA) is enabled for them.
5.4.1.2

How to investigate and maybe solve issues

If the optical disc fails to boot, try the suggestions listed below.
• Check that your BIOS/UEFI actually supports booting from optical disc (only an issue for very old systems)
and that booting from such media is enabled in the BIOS/UEFI.
• If you downloaded an iso image, check that the md5sum of that image matches the one listed for the image in
the MD5SUMS file that should be present in the same location as where you downloaded the image from.
$ md5sum debian-testing-i386-netinst.isoa20391b12f7ff22ef705cee4059c6b92 debian-testing-i386-netinst.iso

Next, check that the md5sum of the burned disc matches as well. The following command should work. It uses
the size of the image to read the correct number of bytes from the disc.
$ dd if=/dev/cdrom | \> head -c ‘stat --format=%s debian-testing-i386-netinst.iso‘ | \> md5suma20391b12f7ff22ef705cee4059c6b92 262668+0 records in
262668+0 records out
134486016 bytes (134 MB) copied, 97.474 seconds, 1.4 MB/s

If, after the installer has been booted successfully, the disc is not detected, sometimes simply trying again may
solve the problem. If you have more than one optical drive, try changing the disc to the other drive. If that does notwork or if the disc is recognized but there are errors when reading from it, try the suggestions listed below. Somebasic knowledge of Linux is required for this. To execute any of the commands, you should first switch to the second
virtual console (VT2) and activate the shell there.
• Switch to VT4 or view the contents of /var/log/syslog (use nano as editor) to check for any specificerror messages. After that, also check the output of dmesg.
• Check in the output of dmesg if your optical drive was recognized. You should see something like (the lines
do not necessarily have to be consecutive):

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5.4. TROUBLESHOOTING THE INSTALLATION …

ata1.00: ATAPI: MATSHITADVD-RAM UJ-822S, 1.61, max UDMA/33
ata1.00: configured for UDMA/33
scsi 0:0:0:0: CD-ROM
MATSHITA DVD-RAM UJ-822S 1.61 PQ: 0 ANSI: 5
sr0: scsi3-mmc drive: 24x/24x writer dvd-ram cd/rw xa/form2 cdda tray
cdrom: Uniform CD-ROM driver Revision: 3.20

If you don’t see something like that, chances are the controller your drive is connected to was not recognizedor may be not supported at all. If you know what driver is needed for the controller, you can try loading it
manually using modprobe.
• Check that there is a device node for your optical drive under /dev/. In the example above, this would be/dev/sr0. There should also be a /dev/cdrom.
• Use the mount command to check if the optical disc is already mounted; if not, try mounting it manually:$ mount /dev/hdc /cdrom

Check if there are any error messages after that command.
• Check if DMA is currently enabled:$ cd /proc/ide/hdc$ grep using_dma settings
using_dma
1
0

1

rw

A “1” in the first column after using_dma means it is enabled. If it is, try disabling it:$ echo -n ”using_dma:0” >settings

Make sure that you are in the directory for the device that corresponds to your optical drive.
• If there are any problems during the installation, try checking the integrity of the installation media using theoption near the bottom of the installer’s main menu. This option can also be used as a general test if the disccan be read reliably.

5.4.2

Boot Configuration

If you have problems and the kernel hangs during the boot process, doesn’t recognize peripherals you actually have,or drives are not recognized properly, the first thing to check is the boot parameters, as discussed in Section 5.3.
In some cases, malfunctions can be caused by missing device firmware (see Section 2.2 and Section 6.4).

5.4.3

Interpreting the Kernel Startup Messages

During the boot sequence, you may see many messages in the form can’t find something , or something
not present, can’t initialize something , or even this driver release depends on something .
Most of these messages are harmless. You see them because the kernel for the installation system is built to run on
computers with many different peripheral devices. Obviously, no one computer will have every possible peripheraldevice, so the operating system may emit a few complaints while it looks for peripherals you don’t own. You may
also see the system pause for a while. This happens when it is waiting for a device to respond, and that device is notpresent on your system. If you find the time it takes to boot the system unacceptably long, you can create a custom
kernel later (see Section 8.5).

5.4.4

Reporting Installation Problems

If you get through the initial boot phase but cannot complete the install, the menu option Save debug logs may be
helpful. It lets you store system error logs and configuration information from the installer on a storage medium, or
download them using a web browser. This information may provide clues as to what went wrong and how to fix it. If
you are submitting a bug report, you may want to attach this information to the bug report.
Other pertinent installation messages may be found in /var/log/ during the installation, and /var/log/
installer/ after the computer has been booted into the installed system.

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5.4.5

5.4. TROUBLESHOOTING THE INSTALLATION …

Submitting Installation Reports

If you still have problems, please submit an installation report (in English please, whenever possible). We also encourage installation reports to be sent even if the installation is successful, so that we can get as much information as
possible on the largest number of hardware configurations.
Note that your installation report will be published in the Debian Bug Tracking System (BTS) and forwarded to a
public mailing list. Make sure that you use an e-mail address that you do not mind being made public.
If you have a working Debian system, the easiest way to send an installation report is to install the installation-reportand reportbug packages (apt install installation-report reportbug), configure reportbug as explained in Section 8.4.2, and run the command reportbug installation-reports.
Alternatively you can use this template when filling out installation reports, and file the report as a bug reportagainst the installation-reports pseudo package, by sending it to submit@bugs.debian.org.
Package: installation-reports
Boot method: <How did you boot the installer? CD/DVD? USB stick? Network?>
Image version: <Full URL to image you downloaded is best>
Date: <Date and time of the install>
Machine: <Description of machine (eg, IBM Thinkpad R32)>
Processor:
Memory:Partitions: <df -Tl will do; the raw partition table is preferred>
Output of lspci -knn (or lspci -nn):
Base System Installation Checklist:[O] = OK, [E] = Error (please elaborate below), [ ] = didn’t try it
Initial boot:[ ]Detect network card:[ ]Configure network:[ ]Detect media:[ ]Load installer modules: [ ]Detect hard drives:[ ]Partition hard drives: [ ]Install base system:[ ]Clock/timezone setup:[ ]User/password setup:[ ]Install tasks:[ ]Install boot loader:[ ]Overall install:[ ]Comments/Problems:<Description of the install, in prose, and any thoughts, comments
and ideas you had during the initial install.>Please make sure that any installation logs that you think would
be useful are attached to this report. (You can find them in the installer
system in /var/log/ and later on the installed system under/var/log/installer.) Please compress large files using gzip.

In the bug report, describe what the problem is, including the last visible kernel messages in the event of a kernel hang.
Describe the steps that you did which brought the system into the problem state.

30Chapter 6

Using the Debian Installer
6.1

How the Installer Works

For this architecture the debian-installer supports two different user interfaces: a text-based one and a graphical one. The text-based interface is used by default unless you select an “Graphical install” option in the boot menu.
For more information about booting the graphical installer, please refer to Section 5.1.6.
The Debian Installer consists of a number of special-purpose components to perform each installation task. Eachcomponent performs its task, asking the user questions as necessary to do its job. The questions themselves are given
priorities, and the priority of questions to be asked is set when the installer is started.
When a default installation is performed, only essential (high priority) questions will be asked. This results ina highly automated installation process with little user interaction. Components are automatically run in sequence;
which components are run depends mainly on the installation method you use and on your hardware. The installer
will use default values for questions that are not asked.
If there is a problem, the user will see an error screen, and the installer menu may be shown in order to selectsome alternative action. If there are no problems, the user will never see the installer menu, but will simply answer
questions for each component in turn. Serious error notifications are set to priority “critical” so the user will always
be notified.
Some of the defaults that the installer uses can be influenced by passing boot arguments when debian-installer
is started. If, for example, you wish to force static network configuration (IPv6 autoconfiguration and DHCP are usedby default if available), you could add the boot parameter netcfg/disable_autoconfig=true. See Section 5.3.2 for available options.
Power users may be more comfortable with a menu-driven interface, where each step is controlled by the user
rather than the installer performing each step automatically in sequence. To use the installer in a manual, menu-driven
way, add the boot argument priority=medium.
If your hardware requires you to pass options to kernel modules as they are installed, you will need to start the
installer in “expert” mode. This can be done by either using the expert command to start the installer or by adding
the boot argument priority=low. Expert mode gives you full control over debian-installer.
In the text-based environment the use of a mouse is not supported. Here are the keys you can use to navigate
within the various dialogs. The Tab or right arrow keys move “forward”, and the Shift-Tab or left arrow keys move“backward” between displayed buttons and selections. The up and down arrow select different items within a scrollable
list, and also scroll the list itself. In addition, in long lists, you can type a letter to cause the list to scroll directly to thesection with items starting with the letter you typed and use Pg-Up and Pg-Down to scroll the list in sections. The
space bar selects an item such as a checkbox. Use Enter to activate choices.
Some dialogs may offer additional help information. If help is available this will be indicated on the bottom lineof the screen by displaying that help information can be accessed by pressing the F1 key.
Error messages and logs are redirected to the fourth console. You can access this console by pressing Left Alt-F4(hold the left Alt key while pressing the F4 function key); get back to the main installer process with Left Alt-F1.
These messages can also be found in /var/log/syslog. After installation, this log is copied to /var/log/
installer/syslog on your new system. Other installation messages may be found in /var/log/ during the
installation, and /var/log/installer/ after the computer has been booted into the installed system.

6.1.1

Using the graphical installer

The graphical installer basically works the same as the text-based installer and thus the rest of this manual can be used
to guide you through the installation process.
31CHAPTER 6. USING THE DEBIAN INSTALLER

6.2. COMPONENTS INTRODUCTION

If you prefer using the keyboard over the mouse, there are two things you need to know. To expand a collapsed list
(used for example for the selection of countries within continents), you can use the + and - keys. For questions wheremore than one item can be selected (e.g. task selection), you first need to tab to the Continue button after making
your selections; hitting enter will toggle a selection, not activate Continue.
If a dialog offers additional help information, a Help button will be displayed. The help information can be accessed
either by activating the button or by pressing the F1 key.
To switch to another console, you will also need to use the Ctrl key, just as with the X Window System. For
example, to switch to VT2 (the first debug shell) you would use: Ctrl-Left Alt-F2. The graphical installer itself runs
on VT5, so you can use Left Alt-F5 to switch back.

6.2

Components Introduction

Here is a list of installer components with a brief description of each component’s purpose. Details you might needto know about using a particular component are in Section 6.3.
main-menu Shows the list of components to the user during installer operation, and starts a component when it isselected. Main-menu’s questions are set to priority medium, so if your priority is set to high or critical (high isthe default), you will not see the menu. On the other hand, if there is an error which requires your intervention,
the question priority may be downgraded temporarily to allow you to resolve the problem, and in that case themenu may appear.
You can get to the main menu by selecting the Go Back button repeatedly to back all the way out of the currently
running component.
localechooser Allows the user to select localization options for the installation and the installed system: language,
country and locales. The installer will display messages in the selected language, unless the translation for that
language is not complete in which case some messages may be shown in English.
console-setup Shows a list of keyboard (layouts), from which the user chooses the one which matches his own model.
hw-detect Automatically detects most of the system’s hardware, including network cards, disk drives, and PCMCIA.
cdrom-detect Looks for and mounts a Debian installation media.
netcfg Configures the computer’s network connections so it can communicate over the internet.
iso-scan Searches for ISO images (.iso files) on hard drives.
choose-mirror Presents a list of Debian archive mirrors. The user may choose the source of his installation packages.
cdrom-checker Checks integrity of installation media. This way, the user may assure him/herself that the installation
image was not corrupted.
lowmem Lowmem tries to detect systems with low memory and then does various tricks to remove unnecessary partsof debian-installer from the memory (at the cost of some features).
anna Anna’s Not Nearly APT. Installs packages which have been retrieved from the chosen mirror or installation
media.
user-setup Sets up the root password, and adds a non-root user.
clock-setup Updates the system clock and determines whether the clock is set to UTC or not.
tzsetup Selects the time zone, based on the location selected earlier.
partman Allows the user to partition disks attached to the system, create file systems on the selected partitions, andattach them to the mountpoints. Included are also interesting features like a fully automatic mode or LVM
support. This is the preferred partitioning tool in Debian.
partman-lvm Helps the user with the configuration of the LVM (Logical Volume Manager).
partman-md Allows the user to set up Software RAID (Redundant Array of Inexpensive Disks). This Software
RAID is usually superior to the cheap IDE (pseudo hardware) RAID controllers found on newer motherboards.
base-installer Installs the most basic set of packages which would allow the computer to operate under Debian
GNU/Linux when rebooted.
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6.3. USING INDIVIDUAL COMPONENTS

apt-setup Configures apt, mostly automatically, based on what media the installer is running from.
pkgsel Uses tasksel to select and install additional software.
os-prober Detects currently installed operating systems on the computer and passes this information to the bootloaderinstaller, which may offer you an ability to add discovered operating systems to the bootloader’s start menu.
This way the user could easily choose at the boot time which operating system to start.
bootloader-installer The various bootloader installers each install a boot loader program on the hard disk, which isnecessary for the computer to start up using Linux without using a USB stick or CD-ROM. Many boot loaders
allow the user to choose an alternate operating system each time the computer boots.
shell Allows the user to execute a shell from the menu, or in the second console.
save-logs Provides a way for the user to record information on a USB stick, network, hard disk, or other media whentrouble is encountered, in order to accurately report installer software problems to Debian developers later.

6.3

Using Individual Components

In this section we will describe each installer component in detail. The components have been grouped into stages
that should be recognizable for users. They are presented in the order they appear during the install. Note that not all
modules will be used for every installation; which modules are actually used depends on the installation method you
use and on your hardware.

6.3.1

Setting up Debian Installer and Hardware Configuration

Let’s assume the Debian Installer has booted and you are facing its first screen. At this time, the capabilities ofdebian-installer are still quite limited. It doesn’t know much about your hardware, preferred language, oreven the task it should perform. Don’t worry. Because debian-installer is quite clever, it can automaticallyprobe your hardware, locate the rest of its components and upgrade itself to a capable installation system. However,
you still need to help debian-installer with some information it can’t determine automatically (like selecting
your preferred language, keyboard layout or desired network mirror).
You will notice that debian-installer performs hardware detection several times during this stage. The
first time is targeted specifically at the hardware needed to load installer components (e.g. your CD-ROM or networkcard). As not all drivers may be available during this first run, hardware detection needs to be repeated later in theprocess.
During hardware detection debian-installer checks if any of the drivers for the hardware devices in yoursystem require firmware to be loaded. If any firmware is requested but unavailable, a dialog will be displayed thatallows the missing firmware to be loaded from a removable medium. See Section 6.4 for further details.
6.3.1.1

Check available memory / low memory mode

One of the first things debian-installer does, is to check available memory. If the available memory is limited,
this component will make some changes in the installation process which hopefully will allow you to install Debian
GNU/Linux on your system.
The first measure taken to reduce memory consumption by the installer is to disable translations, which means thatthe installation can only be done in English. Of course, you can still localize the installed system after the installation
has completed.
If that is not sufficient, the installer will further reduce memory consumption by loading only those components
essential to complete a basic installation. This reduces the functionality of the installation system. You will be given
the opportunity to load additional components manually, but you should be aware that each component you select will
use additional memory and thus may cause the installation to fail.
If the installer runs in low memory mode, it is recommended to create a relatively large swap partition (64–128MB). The swap partition will be used as virtual memory and thus increases the amount of memory available to thesystem. The installer will activate the swap partition as early as possible in the installation process. Note that heavy
use of swap will reduce performance of your system and may lead to high disk activity.
Despite these measures, it is still possible that your system freezes, that unexpected errors occur or that processes
are killed by the kernel because the system runs out of memory (which will result in “Out of memory” messages on
VT4 and in the syslog).

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6.3. USING INDIVIDUAL COMPONENTS

For example, it has been reported that creating a big ext3 file system fails in low memory mode when there
is insufficient swap space. If a larger swap doesn’t help, try creating the file system as ext2 (which is an essential
component of the installer) instead. It is possible to change an ext2 partition to ext3 after the installation.
It is possible to force the installer to use a higher lowmem level than the one based on available memory by using
the boot parameter “lowmem” as described in Section 5.3.2.
6.3.1.2

Selecting Localization Options

In most cases the first questions you will be asked concern the selection of localization options to be used both for the
installation and for the installed system. The localization options consist of language, location and locales.
The language you choose will be used for the rest of the installation process, provided a translation of the different
dialogs is available. If no valid translation is available for the selected language, the installer will default to English.
The selected geographic location (in most cases a country) will be used later in the installation process to selectthe correct time zone and a Debian mirror appropriate for that country. Language and country together will help
determine the default locale for your system and select the correct keyboard layout.
You will first be asked to select your preferred language. The language names are listed both in English (left side)and in the language itself (right side); the names on the right side are also shown in the proper script for the language.
The list is sorted on the English names. At the top of the list is an extra option that allows you to select the “C” locale
instead of a language. Choosing the “C” locale will result in the installation proceeding in English; the installed system
will have no localization support as the locales package will not be installed.
Next you will be asked to select your geographic location. If you selected a language that is recognized as an
official language for more than one country¹, you will be shown a list of only those countries. To select a country
that is not in that list, choose other (the last option). You will then be presented with a list of continents; selecting acontinent will lead to a list of relevant countries on that continent.
If the language has only one country associated with it, a list of countries will be displayed for the continent or
region the country belongs to, with that country selected as the default. Use the Go Back option to select countries ona different continent.

NOTE
It is important to select the country where you live or where you are located as it
determines the time zone that will be configured for the installed system.
If you selected a combination of language and country for which no locale is defined and there exist multiple
locales for the language, then the installer will allow you to choose which of those locales you prefer as the default
locale for the installed system². In all other cases a default locale will be selected based on the selected language andcountry.
Any default locale selected as described in the previous paragraph will use UTF-8 as character encoding.
If you are installing at low priority, you will have the option of selecting additional locales, including so-called“legacy” locales³, to be generated for the installed system; if you do, you will be asked which of the selected locales
should be the default for the installed system.
6.3.1.3

Choosing a Keyboard

Keyboards are often tailored to the characters used in a language. Select a layout that conforms to the keyboard you
are using, or select something close if the keyboard layout you want isn’t represented. Once the system installation iscomplete, you’ll be able to select a keyboard layout from a wider range of choices (run dpkg-reconfigure keyboardconfiguration as root after you have completed the installation).
¹In technical terms: where multiple locales exist for that language with differing country codes.
²At medium and low priority you can always select your preferred locale from those available for the selected language (if there’s more thanone).
³Legacy locales are locales which do not use UTF-8, but one of the older standards for character encoding such as ISO 8859-1 (used by West
European languages) or EUC-JP (used by Japanese).

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Move the highlight to the keyboard selection you desire and press Enter. Use the arrow keys to move the highlight— they are in the same place in all national language keyboard layouts, so they are independent of the keyboard
configuration.
6.3.1.4

Looking for the Debian Installer ISO Image

When installing via the hd-media method, there will be a moment where you need to find and mount the DebianInstaller iso image in order to get the rest of the installation files. The component iso-scan does exactly this.
At first, iso-scan automatically mounts all block devices (e.g. partitions and logical volumes) which have someknown filesystem on them and sequentially searches for filenames ending with .iso (or .ISO for that matter).
Beware that the first attempt scans only files in the root directory and in the first level of subdirectories (i.e. it finds/whatever.iso, /data/whatever.iso, but not /data/tmp/whatever.iso). After an iso image has beenfound, iso-scan checks its content to determine if the image is a valid Debian iso image or not. In the former case weare done, in the latter iso-scan seeks for another image.
In case the previous attempt to find an installer iso image fails, iso-scan will ask you whether you would like toperform a more thorough search. This pass doesn’t just look into the topmost directories, but really traverses wholefilesystem.
If iso-scan does not discover your installer iso image, reboot back to your original operating system and check if
the image is named correctly (ending in .iso), if it is placed on a filesystem recognizable by debian-installer,
and if it is not corrupted (verify the checksum). Experienced Unix users could do this without rebooting on the second
console.
Note that the partition (or disk) hosting the ISO image can’t be reused during the installation process as it will be inuse by the installer. To work-around this, and provided that you have enough system memory, the installer can copy the
ISO image into RAM before mounting it. This is controlled by the low priority iso-scan/copy_iso_to_ram
debconf question (it is only asked if the memory requirement is met).
6.3.1.5

Configuring the Network

As you enter this step, if the system detects that you have more than one network device, you’ll be asked to choose
which device will be your primary network interface, i.e. the one which you want to use for installation. The otherinterfaces won’t be configured at this time. You may configure additional interfaces after installation is complete; see
the interfaces(5) man page.
6.3.1.5.1

Automatic network configuration

By default, debian-installer tries to configure your computer’s network automatically as far as possible. If
the automatic configuration fails, that may be caused by many factors ranging from an unplugged network cable tomissing infrastructure for automatic configuration. For further explanation in case of errors, check the error messages
on the fourth console. In any case, you will be asked if you want to retry, or if you want to perform a manual
setup. Sometimes the network services used for autoconfiguration can be slow in their responses, so if you are sureeverything is in place, simply start the autoconfiguration attempt again. If autoconfiguration fails repeatedly, you caninstead choose the manual network setup.
6.3.1.5.2

Manual network configuration

The manual network setup in turn asks you a number of questions about your network, notably IP address,
Netmask, Gateway, Name server addresses, and a Hostname. Moreover, if you have a wireless network interface, you will be asked to provide your Wireless ESSID (“wireless network name”) and a WEP key
or WPA/WPA2 passphrase. Fill in the answers from Section 3.3.

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NOTE
Some technical details you might, or might not, find handy: the program assumes
the network IP address is the bitwise-AND of your system’s IP address and yournetmask. The default broadcast address is calculated as the bitwise OR of yoursystem’s IP address with the bitwise negation of the netmask. It will also guess
your gateway. If you can’t find any of these answers, use the offered defaults — ifnecessary, you can change them by editing /etc/network/interfaces oncethe system has been installed.

6.3.1.5.3

IPv4 and IPv6

From Debian GNU/Linux 7.0 (“Wheezy”) onwards, debian-installer supports IPv6 as well as the “classic”
IPv4. All combinations of IPv4 and IPv6 (IPv4-only, IPv6-only and dual-stack configurations) are supported.
Autoconfiguration for IPv4 is done via DHCP (Dynamic Host Configuration Protocol). Autoconfiguration forIPv6 supports stateless autoconfiguration using NDP (Neighbor Discovery Protocol, including recursive DNS server(RDNSS) assignment), stateful autoconfiguration via DHCPv6 and mixed stateless/stateful autoconfiguration (addressconfiguration via NDP, additional parameters via DHCPv6).

6.3.2

Setting Up Users And Passwords

Just before configuring the clock, the installer will allow you to set up the “root” account and/or an account for the
first user. Other user accounts can be created after the installation has been completed.
6.3.2.1

Set the Root Password

The root account is also called the super-user; it is a login that bypasses all security protection on your system. The
root account should only be used to perform system administration, and only used for as short a time as possible.
Any password you create should contain at least 6 characters, and should contain both upper- and lower-casecharacters, as well as punctuation characters. Take extra care when setting your root password, since it is such a
powerful account. Avoid dictionary words or use of any personal information which could be guessed.
If anyone ever tells you they need your root password, be extremely wary. You should normally never give yourroot password out, unless you are administering a machine with more than one system administrator.
In case you do not specify a password for the “root” user here, this account will be disabled but the sudo package
will be installed later to enable administrative tasks to be carried out on the new system. By default, the first user
created on the system will be allowed to use the sudo command to become root.
6.3.2.2

Create an Ordinary User

The system will ask you whether you wish to create an ordinary user account at this point. This account should be
your main personal log-in. You should not use the root account for daily use or as your personal login.
Why not? Well, one reason to avoid using root’s privileges is that it is very easy to do irreparable damage as
root. Another reason is that you might be tricked into running a Trojan-horse program — that is a program that takes
advantage of your super-user powers to compromise the security of your system behind your back. Any good bookon Unix system administration will cover this topic in more detail — consider reading one if it is new to you.
You will first be prompted for the user’s full name. Then you’ll be asked for a name for the user account; generally
your first name or something similar will suffice and indeed will be the default. Finally, you will be prompted for apassword for this account.
If at any point after installation you would like to create another account, use the adduser command.

6.3.3

Configuring the Clock and Time Zone

The installer will first attempt to connect to a time server on the Internet (using the NTP protocol) in order to correctly
set the system time. If this does not succeed, the installer will assume the time and date obtained from the system
clock when the installation system was booted are correct. It is not possible to manually set the system time during
the installation process.

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Depending on the location selected earlier in the installation process, you may be shown a list of time zones relevant
for that location. If your location has only one time zone and you are doing a default installation, you will not be asked
anything and the system will assume that time zone.
In expert mode or when installing at medium priority, you will have the additional option to select “Coordinated
Universal Time” (UTC) as time zone.
If for some reason you wish to set a time zone for the installed system that does not match the selected location,
there are two options.
1. The simplest option is to just select a different time zone after the installation has been completed and you’vebooted into the new system. The command to do this is:# dpkg-reconfigure tzdata

2. Alternatively, the time zone can be set at the very start of the installation by passing the parameter time/zone=value
when you boot the installation system. The value should of course be a valid time zone, for example Europe/London
or UTC.
For automated installations the time zone can be set to any desired value using preseeding.

6.3.4

Partitioning and Mount Point Selection

At this time, after hardware detection has been executed a final time, debian-installer should be at its fullstrength, customized for the user’s needs and ready to do some real work. As the title of this section indicates, themain task of the next few components lies in partitioning your disks, creating filesystems, assigning mountpoints andoptionally configuring closely related options like RAID, LVM or encrypted devices.
If you are uncomfortable with partitioning, or just want to know more details, see Appendix C.
First you will be given the opportunity to automatically partition either an entire drive, or available free space ona drive. This is also called “guided” partitioning. If you do not want to autopartition, choose Manual from the menu.
6.3.4.1

Supported partitioning options

The partitioner used in debian-installer is fairly versatile. It allows to create many different partitioning
schemes, using various partition tables, file systems and advanced block devices.
Exactly which options are available depends mainly on the architecture, but also on other factors. For example,
on systems with limited internal memory some options may not be available. Defaults may vary as well. The type ofpartition table used by default can for example be different for large capacity hard disks than for smaller hard disks.
Some options can only be changed when installing at medium or low debconf priority; at higher priorities sensible
defaults will be used.
The installer supports various forms of advanced partitioning and use of storage devices, which in many cases canbe used in combination.
• Logical Volume Management (LVM)• Software RAID
Supported are RAID levels 0, 1, 4, 5, 6 and 10.
• Encryption• Multipath (experimental)
See our Wiki for information. Support for multipath is currently only available if enabled when the installer isbooted.
The following file systems are supported.
• ext2r0, ext2, ext3, ext4
The default file system selected in most cases is ext4; for /boot partitions ext2 will be selected by default whenguided partitioning is used.
• jfs (not available on all architectures)• xfs (not available on all architectures)

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CHAPTER 6. USING THE DEBIAN INSTALLER

6.3. USING INDIVIDUAL COMPONENTS• reiserfs (optional; not available on all architectures)Support for the Reiser file system is no longer available by default. When the installer is running at medium or
low debconf priority it can be enabled by selecting the partman-reiserfs component. Only version 3 ofthe file system is supported.
• jffs2
Used on some systems to read flash memory. It is not possible to create new jffs2 partitions.
• FAT16, FAT32
6.3.4.2

Guided Partitioning

If you choose guided partitioning, you may have three options: to create partitions directly on the hard disk (classic
method), or to create them using Logical Volume Management (LVM), or to create them using encrypted LVM⁴.

NOTE
The option to use (encrypted) LVM may not be available on all architectures.
When using LVM or encrypted LVM, the installer will create most partitions inside one big partition; the advantageof this method is that partitions inside this big partition can be resized relatively easily later. In the case of encrypted
LVM the big partition will not be readable without knowing a special key phrase, thus providing extra security of your(personal) data.
When using encrypted LVM, the installer will also automatically erase the disk by writing random data to it. Thisfurther improves security (as it makes it impossible to tell which parts of the disk are in use and also makes sure thatany traces of previous installations are erased), but may take some time depending on the size of your disk.

NOTE
If you choose guided partitioning using LVM or encrypted LVM, some changes in
the partition table will need to be written to the selected disk while LVM is being set
up. These changes effectively erase all data that is currently on the selected harddisk and you will not be able to undo them later. However, the installer will ask you
to confirm these changes before they are written to disk.
If you choose guided partitioning (either classic or using (encrypted) LVM) for a whole disk, you will first be
asked to select the disk you want to use. Check that all your disks are listed and, if you have several disks, make sure
you select the correct one. The order they are listed in may differ from what you are used to. The size of the disks
may help to identify them.
Any data on the disk you select will eventually be lost, but you will always be asked to confirm any changes before
they are written to the disk. If you have selected the classic method of partitioning, you will be able to undo any
changes right until the end; when using (encrypted) LVM this is not possible.
Next, you will be able to choose from the schemes listed in the table below. All schemes have their pros andcons, some of which are discussed in Appendix C. If you are unsure, choose the first one. Bear in mind that guided
partitioning needs a certain minimal amount of free space to operate with. If you don’t give it at least about 1GB ofspace (depends on chosen scheme), guided partitioning will fail.
Partitioning scheme
All files in one partition
Separate /home partition
Separate /home, /var and /tmp
partitions

Minimum space
600MB
500MB

Created partitions/, swap/, /home, swap

1GB/, /home, /var, /tmp, swap

⁴The installer will encrypt the LVM volume group using a 256 bit AES key and makes use of the kernel’s “dm-crypt” support.

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If you choose guided partitioning using (encrypted) LVM, the installer will also create a separate /boot partition.
The other partitions, including the swap partition, will be created inside the LVM partition.
If you have booted in EFI mode then within the guided partitioning setup there will be an additional partition,formatted as a FAT32 bootable filesystem, for the EFI boot loader. This partition is known as an EFI System Partition(ESP). There is also an additional menu item in the formatting menu to manually set up a partition as an ESP.
After selecting a scheme, the next screen will show your new partition table, including information on whether
and how partitions will be formatted and where they will be mounted.
The list of partitions might look like this:SCSI1 (0,0,0) (sda) - 6.4 GB WDC AC36400L#1 primary
16.4 MB B f ext2/boot
#2 primary 551.0 MB
swap
swap
#3 primary
5.8 GB
ntfs
pri/log
8.2 MB
FREE SPACESCSI2 (1,0,0) (sdb) - 80.0 GB ST380021A#1 primary
15.9 MBext3#2 primary 996.0 MB
fat16#3 primary
3.9 GBxfs#5 logical
6.0 GBf ext4#6 logical
1.0 GBf ext3#7 logical 498.8 MB
ext3

/home
/
/var

This example shows two hard drives divided into several partitions; the first disk has some free space. Each partitionline consists of the partition number, its type, size, optional flags, file system, and mountpoint (if any). Note: thisparticular setup cannot be created using guided partitioning but it does show possible variation that can be achieved
using manual partitioning.
This concludes the guided partitioning. If you are satisfied with the generated partition table, you can choose
Finish partitioning and write changes to disk from the menu to implement the new partition table (as described at theend of this section). If you are not happy, you can choose to Undo changes to partitions and run guided partitioning
again, or modify the proposed changes as described below for manual partitioning.
6.3.4.3

Manual Partitioning

A similar screen to the one shown just above will be displayed if you choose manual partitioning except that yourexisting partition table will be shown and without the mount points. How to manually set up your partition table andthe usage of partitions by your new Debian system will be covered in the remainder of this section.
If you select a pristine disk which has neither partitions nor free space on it, you will be asked if a new partition
table should be created (this is needed so you can create new partitions). After this, a new line entitled “FREE SPACE”
should appear in the table under the selected disk.
If you select some free space, you will have the opportunity to create a new partition. You will have to answer aquick series of questions about its size, type (primary or logical), and location (beginning or end of the free space).
After this, you will be presented with a detailed overview of your new partition. The main setting is Use as:, which
determines if the partition will have a file system on it, or be used for swap, software RAID, LVM, an encrypted filesystem, or not be used at all. Other settings include mountpoint, mount options, and bootable flag; which settings areshown depends on how the partition is to be used. If you don’t like the preselected defaults, feel free to change themto your liking. E.g. by selecting the option Use as:, you can choose a different filesystem for this partition, including
options to use the partition for swap, software RAID, LVM, or not use it at all. When you are satisfied with your newpartition, select Done setting up the partition and you will return to partman’s main screen.
If you decide you want to change something about your partition, simply select the partition, which will bring
you to the partition configuration menu. This is the same screen as is used when creating a new partition, so you canchange the same settings. One thing that may not be very obvious at a first glance is that you can resize the partition
by selecting the item displaying the size of the partition. Filesystems known to work are at least fat16, fat32, ext2,
ext3 and swap. This menu also allows you to delete a partition.
Be sure to create at least two partitions: one for the root filesystem (which must be mounted as /) and one forswap. If you forget to mount the root filesystem, partman won’t let you continue until you correct this issue.
If you boot in EFI mode but forget to select and format an EFI System Partition, partman will detect this andwill not let you continue until you allocate one.

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Capabilities of partman can be extended with installer modules, but are dependent on your system’s architecture.
So if you can’t see all promised goodies, check if you have loaded all required modules (e.g. partman-ext3,
partman-xfs, or partman-lvm).
After you are satisfied with partitioning, select Finish partitioning and write changes to disk from the partitioning
menu. You will be presented with a summary of changes made to the disks and asked to confirm that the filesystems
should be created as requested.
6.3.4.4

Configuring Multidisk Devices (Software RAID)

If you have more than one harddrive⁵ in your computer, you can use partman-md to set up your drives for increased
performance and/or better reliability of your data. The result is called Multidisk Device (or after its most famous
variant software RAID).
MD is basically a bunch of partitions located on different disks and combined together to form a logical device.
This device can then be used like an ordinary partition (i.e. in partman you can format it, assign a mountpoint, etc.).
What benefits this brings depends on the type of MD device you are creating. Currently supported are:
RAID0 Is mainly aimed at performance. RAID0 splits all incoming data into stripes and distributes them equally
over each disk in the array. This can increase the speed of read/write operations, but when one of the disks
fails, you will lose everything (part of the information is still on the healthy disk(s), the other part was on thefailed disk).
The typical use for RAID0 is a partition for video editing.
RAID1 Is suitable for setups where reliability is the first concern. It consists of several (usually two) equally-sizedpartitions where every partition contains exactly the same data. This essentially means three things. First, if
one of your disks fails, you still have the data mirrored on the remaining disks. Second, you can use only afraction of the available capacity (more precisely, it is the size of the smallest partition in the RAID). Third,
file-reads are load-balanced among the disks, which can improve performance on a server, such as a file server,that tends to be loaded with more disk reads than writes.
Optionally you can have a spare disk in the array which will take the place of the failed disk in the case of
failure.
RAID5 Is a good compromise between speed, reliability and data redundancy. RAID5 splits all incoming data
into stripes and distributes them equally on all but one disk (similar to RAID0). Unlike RAID0, RAID5 also
computes parity information, which gets written on the remaining disk. The parity disk is not static (that would
be called RAID4), but is changing periodically, so the parity information is distributed equally on all disks.
When one of the disks fails, the missing part of information can be computed from remaining data and its
parity. RAID5 must consist of at least three active partitions. Optionally you can have a spare disk in the array
which will take the place of the failed disk in the case of failure.
As you can see, RAID5 has a similar degree of reliability to RAID1 while achieving less redundancy. On theother hand, it might be a bit slower on write operations than RAID0 due to computation of parity information.
RAID6 Is similar to RAID5 except that it uses two parity devices instead of one.
A RAID6 array can survive up to two disk failures.
RAID10 RAID10 combines striping (as in RAID0) and mirroring (as in RAID1). It creates n copies of incoming
data and distributes them across the partitions so that none of the copies of the same data are on the samedevice. The default value of n is 2, but it can be set to something else in expert mode. The number of partitions
used must be at least n. RAID10 has different layouts for distributing the copies. The default is near copies.
Near copies have all of the copies at about the same offset on all of the disks. Far copies have the copies atdifferent offsets on the disks. Offset copies copy the stripe, not the individual copies.
RAID10 can be used to achieve reliability and redundancy without the drawback of having to calculate parity.
To sum it up:

⁵To be honest, you can construct an MD device even from partitions residing on single physical drive, but that won’t give any benefits.

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CHAPTER 6. USING THE DEBIAN INSTALLER

Minimum
DevicesType

6.3. USING INDIVIDUAL COMPONENTS

Spare Device

Survives disk
failure?

RAID0

2

no

no

RAID1

2

optional

yes

RAID5

3

optional

yes

RAID6

4

optional

yes

RAID102

optional

yes

Available Space
Size of the smallest
partition multiplied
by number ofdevices in RAID
Size of the smallest
partition in RAID
Size of the smallest
partition multipliedby (number ofdevices in RAID
minus one)Size of the smallest
partition multipliedby (number ofdevices in RAID
minus two)
Total of allpartitions divided
by the number ofchunk copies(defaults to two)

If you want to know more about Software RAID, have a look at Software RAID HOWTO.
To create an MD device, you need to have the desired partitions it should consist of marked for use in a RAID.
(This is done in partman in the Partition settings menu where you should select Use as: → physical volume for
RAID.)NOTE
Make sure that the system can be booted with the partitioning scheme you are planning. In general it will be necessary to create a separate file system for /boot whenusing RAID for the root (/) file system. Most boot loaders do support mirrored (notstriped!) RAID1, so using for example RAID5 for / and RAID1 for /boot can be
an option.
Next, you should choose Configure software RAID from the main partman menu. (The menu will only appear
after you mark at least one partition for use as physical volume for RAID.) On the first screen of partman-md simply
select Create MD device. You will be presented with a list of supported types of MD devices, from which you shouldchoose one (e.g. RAID1). What follows depends on the type of MD you selected.
• RAID0 is simple — you will be issued with the list of available RAID partitions and your only task is to selectthe partitions which will form the MD.
• RAID1 is a bit more tricky. First, you will be asked to enter the number of active devices and the numberof spare devices which will form the MD. Next, you need to select from the list of available RAID partitions
those that will be active and then those that will be spare. The count of selected partitions must be equal to
the number provided earlier. Don’t worry. If you make a mistake and select a different number of partitions,debian-installer won’t let you continue until you correct the issue.
• RAID5 has a setup procedure similar to RAID1 with the exception that you need to use at least three active
partitions.
• RAID6 also has a setup procedure similar to RAID1 except that at least four active partitions are required.
• RAID10 again has a setup procedure similar to RAID1 except in expert mode. In expert mode, debian-installer
will ask you for the layout. The layout has two parts. The first part is the layout type. It is either n (for near41

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copies), f (for far copies), or o (for offset copies). The second part is the number of copies to make of the data.
There must be at least that many active devices so that all of the copies can be distributed onto different disks.
It is perfectly possible to have several types of MD at once. For example, if you have three 200 GB hard drives
dedicated to MD, each containing two 100 GB partitions, you can combine the first partitions on all three disks into
the RAID0 (fast 300 GB video editing partition) and use the other three partitions (2 active and 1 spare) for RAID1(quite reliable 100 GB partition for /home).
After you set up MD devices to your liking, you can Finish partman-md to return back to the partman to create
filesystems on your new MD devices and assign them the usual attributes like mountpoints.
6.3.4.5

Configuring the Logical Volume Manager (LVM)

If you are working with computers at the level of system administrator or “advanced” user, you have surely seen thesituation where some disk partition (usually the most important one) was short on space, while some other partition
was grossly underused and you had to manage this situation by moving stuff around, symlinking, etc.
To avoid the described situation you can use Logical Volume Manager (LVM). Simply said, with LVM you can
combine your partitions (physical volumes in LVM lingo) to form a virtual disk (so called volume group), which canthen be divided into virtual partitions (logical volumes). The point is that logical volumes (and of course underlying
volume groups) can span across several physical disks.
Now when you realize you need more space for your old 160GB /home partition, you can simply add a new
300GB disk to the computer, join it with your existing volume group and then resize the logical volume which holds
your /home filesystem and voila — your users have some room again on their renewed 460GB partition. This example
is of course a bit oversimplified. If you haven’t read it yet, you should consult the LVM HOWTO.
LVM setup in debian-installer is quite simple and completely supported inside partman. First, you haveto mark the partition(s) to be used as physical volumes for LVM. This is done in the Partition settings menu where
you should select Use as: → physical volume for LVM.

WARNINGBe aware: the new LVM setup will destroy all data on all partitions marked with an
LVM type code. So, if you already have an LVM on some of your disks, and want
to install Debian additionally to that machine, the old (already existing) LVM will be
wiped out! The same counts for partitions, which are (for any reason) misleadingly
marked with an LVM type code, but contain something different (like an encryptedvolume). You need to remove such disks from the system, before performing a new
LVM setup!
When you return to the main partman screen, you will see a new option Configure the Logical Volume Manager.
When you select that, you will first be asked to confirm pending changes to the partition table (if any) and after that
the LVM configuration menu will be shown. Above the menu a summary of the LVM configuration is shown. The
menu itself is context sensitive and only shows valid actions. The possible actions are:
• Display configuration details: shows LVM device structure, names and sizes of logical volumes and more
• Create volume group• Create logical volume• Delete volume group• Delete logical volume• Extend volume group• Reduce volume group• Finish: return to the main partman screen
Use the options in that menu to first create a volume group and then create your logical volumes inside it.
After you return to the main partman screen, any created logical volumes will be displayed in the same way as
ordinary partitions (and you should treat them as such).
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6.3. USING INDIVIDUAL COMPONENTS

Configuring Encrypted Volumes

debian-installer allows you to set up encrypted partitions. Every file you write to such a partition is immediately saved to the device in encrypted form. Access to the encrypted data is granted only after entering the passphraseused when the encrypted partition was originally created. This feature is useful to protect sensitive data in case yourlaptop or hard drive gets stolen. The thief might get physical access to the hard drive, but without knowing the right
passphrase, the data on the hard drive will look like random characters.
The two most important partitions to encrypt are: the home partition, where your private data resides, and theswap partition, where sensitive data might be stored temporarily during operation. Of course, nothing prevents you
from encrypting any other partitions that might be of interest. For example /var where database servers, mail servers
or print servers store their data, or /tmp which is used by various programs to store potentially interesting temporary
files. Some people may even want to encrypt their whole system. Generally the only exception here is the /bootpartition which must remain unencrypted, because historically there was no way to load the kernel from an encrypted
partition. (GRUB is now able to do that, but debian-installer currently lacks native support for encrypted/boot. The setup is therefore covered in a separate document.)

NOTE
Please note that the performance of encrypted partitions will be less than that of
unencrypted ones because the data needs to be decrypted or encrypted for every
read or write. The performance impact depends on your CPU speed, chosen cipher
and a key length.
To use encryption, you have to create a new partition by selecting some free space in the main partitioning menu.
Another option is to choose an existing partition (e.g. a regular partition, an LVM logical volume or a RAID volume).
In the Partition settings menu, you need to select physical volume for encryption at the Use as: option. The menu willthen change to include several cryptographic options for the partition.
The encryption method supported by debian-installer is dm-crypt (included in newer Linux kernels, able
to host LVM physical volumes).
Let’s have a look at the options available when you select encryption via Device-mapper (dm-crypt). As
always: when in doubt, use the defaults, because they have been carefully chosen with security in mind.
Encryption: aes This option lets you select the encryption algorithm (cipher) which will be used to encrypt thedata on the partition. debian-installer currently supports the following block ciphers: aes, blowfish,
serpent, and twofish. It is beyond the scope of this document to discuss the qualities of these different algorithms,
however, it might help your decision to know that in 2000, AES was chosen by the American National Instituteof Standards and Technology as the standard encryption algorithm for protecting sensitive information in the
21st century.
Key size: 256 Here you can specify the length of the encryption key. With a larger key size, the strength of theencryption is generally improved. On the other hand, increasing the length of the key usually has a negative
impact on performance. Available key sizes vary depending on the cipher.
IV algorithm: xts-plain64 The Initialization Vector or IV algorithm is used in cryptography to ensure that applying the cipher on the same clear text data with the same key always produces a unique cipher text. The idea
is to prevent the attacker from deducing information from repeated patterns in the encrypted data.
From the provided alternatives, the default xts-plain64 is currently the least vulnerable to known attacks.
Use the other alternatives only when you need to ensure compatibility with some previously installed systemthat is not able to use newer algorithms.
Encryption key: Passphrase Here you can choose the type of the encryption key for this partition.
Passphrase The encryption key will be computed⁶ on the basis of a passphrase which you will be able to enter
later in the process.
Random key A new encryption key will be generated from random data each time you try to bring up theencrypted partition. In other words: on every shutdown the content of the partition will be lost as the key
⁶Using a passphrase as the key currently means that the partition will be set up using LUKS.

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is deleted from memory. (Of course, you could try to guess the key with a brute force attack, but unlessthere is an unknown weakness in the cipher algorithm, it is not achievable in our lifetime.)
Random keys are useful for swap partitions because you do not need to bother yourself with remembering
the passphrase or wiping sensitive information from the swap partition before shutting down your computer. However, it also means that you will not be able to use the “suspend-to-disk” functionality offeredby newer Linux kernels as it will be impossible (during a subsequent boot) to recover the suspended data
written to the swap partition.
Erase data: yes Determines whether the content of this partition should be overwritten with random data before
setting up the encryption. This is recommended because it might otherwise be possible for an attacker to discern
which parts of the partition are in use and which are not. In addition, this will make it harder to recover any
leftover data from previous installations⁷.
After you have selected the desired parameters for your encrypted partitions, return back to the main partitioning
menu. There should now be a new menu item called Configure encrypted volumes. After you select it, you will be
asked to confirm the deletion of data on partitions marked to be erased and possibly other actions such as writing a
new partition table. For large partitions this might take some time.
Next you will be asked to enter a passphrase for partitions configured to use one. Good passphrases should be
longer than 8 characters, should be a mixture of letters, numbers and other characters and should not contain common
dictionary words or information easily associable with you (such as birthdates, hobbies, pet names, names of family
members or relatives, etc.).

WARNING
Before you input any passphrases, you should have made sure that your keyboard
is configured correctly and generates the expected characters. If you are unsure,
you can switch to the second virtual console and type some text at the prompt. This
ensures that you won’t be surprised later, e.g. by trying to input a passphrase using
a qwerty keyboard layout when you used an azerty layout during the installation.
This situation can have several causes. Maybe you switched to another keyboard
layout during the installation, or the selected keyboard layout might not have been
set up yet when entering the passphrase for the root file system.
If you selected to use methods other than a passphrase to create encryption keys, they will be generated now.
Because the kernel may not have gathered a sufficient amount of entropy at this early stage of the installation, theprocess may take a long time. You can help speed up the process by generating entropy: e.g. by pressing random keys,
or by switching to the shell on the second virtual console and generating some network and disk traffic (downloadingsome files, feeding big files into /dev/null, etc.). This will be repeated for each partition to be encrypted.
After returning to the main partitioning menu, you will see all encrypted volumes as additional partitions which canbe configured in the same way as ordinary partitions. The following example shows a volume encrypted via dm-crypt.
Encrypted volume (sda2_crypt) - 115.1 GB Linux device-mapper#1 115.1 GB F ext3

Now is the time to assign mount points to the volumes and optionally change the file system types if the defaults do
not suit you.
Pay attention to the identifiers in parentheses (sda2_crypt in this case) and the mount points you assigned toeach encrypted volume. You will need this information later when booting the new system. The differences between
the ordinary boot process and the boot process with encryption involved will be covered later in Section 7.2.
Once you are satisfied with the partitioning scheme, continue with the installation.

6.3.5

Installing the Base System

Although this stage is the least problematic, it consumes a significant fraction of the install because it downloads,
verifies and unpacks the whole base system. If you have a slow computer or network connection, this could take sometime.
⁷It is believed that the guys from three-letter agencies can restore the data even after several rewrites of the magnetooptical media, though.

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During installation of the base system, package unpacking and setup messages are redirected to tty4. You canaccess this terminal by pressing Left Alt-F4; get back to the main installer process with Left Alt-F1.
The unpack/setup messages generated during this phase are also saved in /var/log/syslog. You can checkthem there if the installation is performed over a serial console.
As part of the installation, a Linux kernel will be installed. At the default priority, the installer will choose one
for you that best matches your hardware. In lower priority modes, you will be able to choose from a list of available
kernels.
When packages are installed using the package management system, it will by default also install packages thatare recommended by those packages. Recommended packages are not strictly required for the core functionality ofthe selected software, but they do enhance that software and should, in the view of the package maintainers, normally
be installed together with that software.

NOTE
For technical reasons packages installed during the installation of the base system
are installed without their “Recommends”. The rule described above only takes
effect after this point in the installation process.

6.3.6

Installing Additional Software

At this point you have a usable but limited system. Most users will want to install additional software on the system totune it to their needs, and the installer allows you do so. This step can take even longer than installing the base system
if you have a slow computer or network connection.
6.3.6.1

Configuring apt

One of the tools used to install packages on a Debian GNU/Linux system is the program apt, from the apt package⁸. Other front-ends for package management, like aptitude and synaptic, are also in use. These front-ends arerecommended for new users, since they integrate some additional features (package searching and status checks) in anice user interface.
apt must be configured so that it knows from where to retrieve packages. The results of this configuration are written to the file /etc/apt/sources.list. You can examine and edit this file to your liking after the installationis complete.
If you are installing at default priority, the installer will largely take care of the configuration automatically, basedon the installation method you are using and possibly using choices made earlier in the installation. In most cases
the installer will automatically add a security mirror and, if you are installing the stable distribution, a mirror for the“stable-updates” service.
If you are installing at a lower priority (e.g. in expert mode), you will be able to make more decisions yourself.
You can choose whether or not to use the security and/or stable-updates services, and you can choose to add packages
from the “contrib”, “non-free”, and “non-free-firmware” sections of the archive.
6.3.6.1.1

Installing from more than one CD or DVD image

If you are installing from a CD or DVD image that is part of a larger set, the installer will ask if you want to scan
additional installation media. If you have such additional media available, you probably want to do this so the installer
can use the packages included on them.
If you do not have any additional media, that is no problem: using them is not required. If you also do not use a
network mirror (as explained in the next section), it can mean that not all packages belonging to the tasks you selectin the next step of the installation can be installed.

⁸Note that the program which actually installs the packages is called dpkg. However, this program is more of a low-level tool. apt is ahigher-level tool, which will invoke dpkg as appropriate. It knows how to retrieve packages from your installation media, the network, or wherever.
It is also able to automatically install other packages which are required to make the package you’re trying to install work correctly.

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NOTE
Packages are included on CD and DVD images in the order of their popularity. Thismeans that for most uses only the first image of a set is needed and that only very
few people actually use any of the packages included on the last images of a set.
It also means that buying or downloading and burning a full CD set is just a wasteof money as you’ll never use most of them. In most cases you are better off getting
only the first 3 to 8 CDs and installing any additional packages you may need fromthe Internet by using a mirror. The same goes for DVD sets: the first DVD, or maybe
the first two DVDs will cover most needs.
If you do scan multiple installation media, the installer will prompt you to exchange them when it needs packages
from one that isn’t currently in the drive. Note that only discs that belong to the same set should be scanned. The
order in which they are scanned does not really matter, but scanning them in ascending order will reduce the chanceof mistakes.
6.3.6.1.2

Using a network mirror

One question that will be asked during most installs is whether or not to use a network mirror as a source for packages.
In most cases the default answer should be fine, but there are some exceptions.
If you are not installing from a full CD/DVD image, you really should use a network mirror as otherwise you will
end up with only a very minimal system. However, if you have a limited Internet connection it is best not to select thedesktop task in the next step of the installation.
If you are installing from a single full CD image, using a network mirror is not required, but is still strongly
recommended because a single CD image contains only a fairly limited number of packages. If you have a limited
Internet connection it may still be best to not select a network mirror here, but to finish the installation using only
what’s available on the CD image and selectively install additional packages after the installation (i.e. after you haverebooted into the new system).
If you are installing from DVD, any packages needed during the installation should be present on the first DVD
image. Use of a network mirror is optional.
One advantage of adding a network mirror is that updates, that have occurred since the CD/DVD images werecreated and have been included in a point release, will become available for installation, thus extending the life of your
CD/DVD set without compromising the security or stability of the installed system.
In summary: selecting a network mirror is generally a good idea, except if you do not have a good Internet
connection. If the current version of a package is available from installation media, the installer will always use that.
The amount of data that will be downloaded if you do select a mirror thus depends on
1. the tasks you select in the next step of the installation,
2. which packages are needed for those tasks,
3. which of those packages are present on the installation media you have scanned, and
4. whether any updated versions of packages included on the installation media are available from a mirror (eithera regular package mirror, or a mirror for security or stable-updates).
Note that the last point means that, even if you choose not to use a network mirror, some packages may still be
downloaded from the Internet if there is a security or stable-updates update available for them and those services havebeen configured.
6.3.6.1.3

Choosing a network mirror

Unless you chose not to use a network mirror, you will be presented with a list of network mirrors based upon yourcountry selection earlier in the installation process. Choosing the offered default is usually fine.
The offered default is deb.debian.org, which is not a mirror itself but will redirect to a mirror that should be up-todate and fast. These mirrors support TLS (https protocol) and IPv6. This service is maintained by the Debian System
Administration (DSA) team.
A mirror can also be specified by hand by choosing “enter information manually” . You can then specify a mirror
host name and an optional port number. This actually has to be a URL base, i.e. when specifying an IPv6 address,
one has to add square brackets around it, for instance “[2001:db8::1]”.
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If your computer is on an IPv6-only network (which is probably not the case for the vast majority of users), using
the default mirror for your country might not work. All the mirrors in the list are reachable via IPv4, but only someof them can be used via IPv6. As connectivity of individual mirrors can change over time, this information is notavailable in the installer. If there is no IPv6 connectivity for the default mirror for your country, you can either try
some of the other mirrors offered to you or choose the “enter information manually” option. You can then specify“ftp.ipv6.debian.org” as the mirror name, which is an alias for a mirror available via IPv6, although it will probably
not be the fastest possible one.
6.3.6.2

Selecting and Installing Software

During the installation process, you are given the opportunity to select additional software to install. Rather thanpicking individual software packages from the 95584 available packages, this stage of the installation process focuseson selecting and installing predefined collections of software to quickly set up your computer to perform various tasks.
These tasks loosely represent a number of different jobs or things you want to do with your computer, such as“Desktop environment”, “Web server”, or “SSH server”⁹. Section D.2 lists the space requirements for the available
tasks.
Some tasks may be pre-selected based on the characteristics of the computer you are installing. If you disagreewith these selections you can deselect them. You can even opt to install no tasks at all at this point.

TIP
In the standard user interface of the installer, you can use the space bar to toggle
selection of a task.

NOTE
The “Desktop environment” task will install a graphical desktop environment.
By default, debian-installer installs the desktop environment. It is possible tointeractively select a different desktop environment during the installation. It is also
possible to install multiple desktops, but some combinations of desktop may not be
co-installable.
Note that this will only work if the packages needed for the desired desktop environment are actually available. If you are installing using a single full CD image, they
will possibly need to be downloaded from a network mirror as they might not be
available on the CD image due to its limited amount of space. Installing any of theavailable desktop environments this way should work fine if you are using a DVD
image or any other installation method.
The various server tasks will install software roughly as follows. Web server: apache2; SSH server: openssh.
The “Standard system” task will install any package that has a priority “standard”. This includes a lot of common
utilities that are normally available on any Linux or Unix system. You should leave this task selected unless you knowwhat you are doing and want a really minimal system.
If during language selection a default locale other than the “C” locale was selected, tasksel will check if any
localization tasks are defined for that locale and will automatically try to install relevant localization packages. This
includes for example packages containing word lists or special fonts for your language. If a desktop environment was
selected, it will also install appropriate localization packages for that (if available).
Once you’ve selected your tasks, select Continue. At this point, apt will install the packages that are part of theselected tasks. If a particular program needs more information from the user, it will prompt you during this process.
⁹You should know that to present this list, the installer is merely invoking the tasksel program. It can be run at any time after installation to
install more packages (or remove them), or you can use a more fine-grained tool such as aptitude. If you are looking for a specific single package,after installation is complete, simply run aptitude install package, where package is the name of the package you are looking for.

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You should be aware that especially the Desktop task is very large. Especially when installing from a normal
CD-ROM in combination with a mirror for packages not on the CD-ROM, the installer may want to retrieve a lot ofpackages over the network. If you have a relatively slow Internet connection, this can take a long time. There is no
option to cancel the installation of packages once it has started.
Even when packages are included on the CD-ROM, the installer may still retrieve them from the mirror if theversion available on the mirror is more recent than the one included on the CD-ROM. If you are installing the stable
distribution, this can happen after a point release (an update of the original stable release); if you are installing thetesting distribution this will happen if you are using an older image.

6.3.7

Making Your System Bootable

If you are installing a diskless workstation, obviously, booting off the local disk isn’t a meaningful option, and thisstep will be skipped.
6.3.7.1

Detecting other operating systems

Before a boot loader is installed, the installer will attempt to probe for other operating systems which are installed on
the machine. If it finds a supported operating system, you will be informed of this during the boot loader installation
step, and the computer will be configured to boot this other operating system in addition to Debian.
Note that multiple operating systems booting on a single machine is still something of a black art. The automatic
support for detecting and setting up boot loaders to boot other operating systems varies by architecture and even bysubarchitecture. If it does not work you should consult your boot manager’s documentation for more information.
6.3.7.2

Making the system bootable with flash-kernel

As there is no common firmware interface on all ARM platforms, the steps required to make the system bootable on
ARM devices are highly device-dependent. Debian uses a tool called flash-kernel to take care of this. Flash-kernel
contains a database which describes the particular operations that are required to make the system bootable on various
devices. It detects whether the current device is supported, and if yes, performs the necessary operations.
On devices which boot from internal NOR- or NAND-flash memory, flash-kernel writes the kernel and the initial
ramdisk to this internal memory. This method is particularly common on older armel devices. Please note thatmost of these devices do not allow having multiple kernels and ramdisks in their internal flash memory, i.e. running
flash-kernel on them usually overwrites the previous contents of the flash memory!
For ARM systems that use U-Boot as their system firmware and boot the kernel and the initial ramdisk fromexternal storage media (such as MMC/SD-cards, USB mass storage devices or IDE/SATA harddisks), flash-kernel
generates an appropriate boot script to allow autobooting without user interaction.
6.3.7.3

Continue Without Boot Loader

This option can be used to complete the installation even when no boot loader is to be installed, either because thearch/subarch doesn’t provide one, or because none is desired (e.g. you will use existing boot loader).
If you plan to manually configure your bootloader, you should check the name of the installed kernel in /target/
boot. You should also check that directory for the presence of an initrd; if one is present, you will probably have to
instruct your bootloader to use it. Other information you will need are the disk and partition you selected for your /filesystem and, if you chose to install /boot on a separate partition, also your /boot filesystem.

6.3.8

Finishing the Installation

This is the last step in the Debian installation process during which the installer will do any last minute tasks. It mostly
consists of tidying up after the debian-installer.
6.3.8.1

Setting the System Clock

The installer may ask you if the computer’s clock is set to UTC. Normally this question is avoided if possible andthe installer tries to work out whether the clock is set to UTC based on things like what other operating systems are
installed.
In expert mode you will always be able to choose whether or not the clock is set to UTC.
At this point debian-installer will also attempt to save the current time to the system’s hardware clock.
This will be done either in UTC or local time, depending on the selection that was just made.

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6.3. USING INDIVIDUAL COMPONENTS

Reboot the System

You will be prompted to remove the boot media (CD, USB stick, etc) that you used to boot the installer. After thatthe system will be rebooted into your new Debian system.

6.3.9

Troubleshooting

The components listed in this section are usually not involved in the installation process, but are waiting in the background to help the user in case something goes wrong.
6.3.9.1

Saving the installation logs

If the installation is successful, the logfiles created during the installation process will be automatically saved to /var/
log/installer/ on your new Debian system.
Choosing Save debug logs from the main menu allows you to save the log files to a USB stick, network, hard disk,or other media. This can be useful if you encounter fatal problems during the installation and wish to study the logs
on another system or attach them to an installation report.
6.3.9.2

Using the Shell and Viewing the Logs

There are several methods you can use to get a shell while running an installation. On most systems, and if you are notinstalling over serial console, the easiest method is to switch to the second virtual console by pressing Left Alt-F2¹⁰(on a Mac keyboard, Option-F2). Use Left Alt-F1 to switch back to the installer itself.
For the graphical installer see also Section 6.1.1.
If you cannot switch consoles, there is also an Execute a Shell item on the main menu that can be used to start ashell. You can get to the main menu from most dialogs by using the Go Back button one or more times. Type exit
to close the shell and return to the installer.
At this point you are booted from the RAM disk, and there is a limited set of Unix utilities available for your use.
You can see what programs are available with the command ls /bin /sbin /usr/bin /usr/sbin and by typing help. The
shell is a Bourne shell clone called ash and has some nice features like autocompletion and history.
To edit and view files, use the text editor nano. Log files for the installation system can be found in the /var/log
directory.

NOTE
Although you can do basically anything in a shell that the available commands allow
you to do, the option to use a shell is really only there in case something goes wrong
and for debugging.
Doing things manually from the shell may interfere with the installation process andresult in errors or an incomplete installation. In particular, you should always use
let the installer activate your swap partition and not do this yourself from a shell.

6.3.10Installation over network-console

One of the more interesting components is network-console. It allows you to do a large part of the installation over the
network via SSH. The use of the network implies you will have to perform the first steps of the installation from theconsole, at least to the point of setting up the networking. (Although you can automate that part with Section 4.5.)
This component is not loaded into the main installation menu by default, so you have to explicitly ask for it. If you
are installing from optical media, you need to boot with medium priority or otherwise invoke the main installation
menu and choose Load installer components from installation media and from the list of additional components selectnetwork-console: Continue installation remotely using SSH. Successful load is indicated by a new menu entry called
Continue installation remotely using SSH.
After selecting this new entry, you will be asked for a new password to be used for connecting to the installation
system and for its confirmation. That’s all. Now you should see a screen which instructs you to login remotely as the¹⁰That is: press the Alt key on the left-hand side of the space bar and the F2 function key at the same time.

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user installer with the password you just provided. Another important detail to notice on this screen is the fingerprintof this system. You need to transfer the fingerprint securely to the person who will continue the installation remotely.
Should you decide to continue with the installation locally, you can always press Enter, which will bring you backto the main menu, where you can select another component.
Now let’s switch to the other side of the wire. As a prerequisite, you need to configure your terminal for UTF-8
encoding, because that is what the installation system uses. If you do not, remote installation will be still possible,
but you may encounter strange display artefacts like destroyed dialog borders or unreadable non-ascii characters.
Establishing a connection with the installation system is as simple as typing:$ ssh -l installer install_host

Where install_host is either the name or IP address of the computer being installed. Before the actual login thefingerprint of the remote system will be displayed and you will have to confirm that it is correct.

NOTE
The ssh server in the installer uses a default configuration that does not send keepalive packets. In principle, a connection to the system being installed should be
kept open indefinitely. However, in some situations — depending on your local network setup — the connection may be lost after some period of inactivity. One common case where this can happen is when there is some form of Network Address
Translation (NAT) somewhere between the client and the system being installed.
Depending on at which point of the installation the connection was lost, you may or
may not be able to resume the installation after reconnecting.
You may be able to avoid the connection being dropped by adding the option-o ServerAliveInterval=value when starting the ssh connection, or byadding that option in your ssh configuration file. Note however that in some cases
adding this option may also cause a connection to be dropped (for example if keepalive packets are sent during a brief network outage, from which ssh would otherwise have recovered), so it should only be used when needed.

NOTE
If you install several computers in turn and they happen to have the same IP addressor hostname, ssh will refuse to connect to such host. The reason is that it will havedifferent fingerprint, which is usually a sign of a spoofing attack. If you are sure this is
not the case, you will need to delete the relevant line from ~/.ssh/known_hostsa
and try again.
aThe following command will
<hostname|IP address>.

removeanexisting

entry

for

a

host:

ssh-keygen-R

After the login you will be presented with an initial screen where you have two possibilities called Start menu andStart shell. The former brings you to the main installer menu, where you can continue with the installation as usual.
The latter starts a shell from which you can examine and possibly fix the remote system. You should only start one
SSH session for the installation menu, but may start multiple sessions for shells.

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6.4. LOADING MISSING FIRMWAREWARNING
After you have started the installation remotely over SSH, you should not go backto the installation session running on the local console. Doing so may corrupt the
database that holds the configuration of the new system. This in turn may result ina failed installation or problems with the installed system.

6.4

Loading Missing Firmware

As described in Section 2.2, some devices require firmware to be loaded. In most cases the device will not work at allif the firmware is not available; sometimes basic functionality is not impaired if it is missing and the firmware is only
needed to enable additional features.
Starting with Debian GNU/Linux 12.0, following the 2022 General Resolution about non-free firmware, official
installation images (like netinst) can include non-free firmware packages. Even with those firmware packages available,some firmware files might still be missing. Or one might be using netboot files, which don’t include firmware packages.
If a device driver requests firmware that is not available, debian-installer will display a dialog offering toload the missing firmware. If this option is selected, debian-installer will scan available devices for either
loose firmware files or packages containing firmware. If found, the firmware will be copied to the correct location(/lib/firmware) and the driver module will be reloaded.

NOTE
Which devices are scanned and which file systems are supported depends on thearchitecture, the installation method and the stage of the installation. Especially during the early stages of the installation, loading the firmware is most likely to succeed
from a FAT-formatted USB stick.
Note that it is possible to skip loading the firmware if you know the device will also function without it, or if thedevice is not needed during the installation.

6.4.1

Preparing a medium

The most common method to load such firmware is from some removable medium such as a USB stick. To preparea USB stick (or other medium like a hard drive partition), the firmware files or packages must be placed in either theroot directory or a directory named /firmware of the file system on the medium. The recommended file system
to use is FAT as that is most certain to be supported during the early stages of the installation.
Tarballs and zip files containing current packages for the most common firmware, and the associated metadata toensure a proper detection by the installer (dep11 directory), are available from:• https://cdimage.debian.org/cdimage/firmware/bookworm/
Just download the tarball or zip file for the correct release and unpack it to the file system on the medium.
It is also possible to copy individual firmware files to the medium. Loose firmware could be obtained for example
from an already installed system or from a hardware vendor.

6.4.2

Firmware and the Installed System

Any firmware loaded during the installation will be copied automatically to the installed system. In most cases thiswill ensure that the device that requires the firmware will also work correctly after the system is rebooted into theinstalled system. However, if the installed system runs a different kernel version than the installer, there is a slightchance that the firmware cannot be loaded due to version skew.
If the firmware was loaded from a firmware package, debian-installer will also install this package for the
installed system and will automatically add the non-free-firmware section of the package archive in APT’s sources.
list. This has the advantage that the firmware should be updated automatically if a new version becomes available.

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6.5. CUSTOMIZATION

If loading the firmware was skipped during the installation, the relevant device will probably not work with the
installed system until the firmware (package) is installed manually.

NOTE
If the firmware was loaded from loose firmware files, the firmware copied to the installed system will not be automatically updated unless the corresponding firmware
package (if available) is installed after the installation is completed.

6.4.3

Completing the Installed System

Depending on how the installation was performed, it might be that the need for some firmware was not detected during
installation, that the relevant firmware was not available, or that one chose not to install some firmware at that time.
In some cases, a successful installation can still end up in a black screen or a garbled display when rebooting into theinstalled system. When that happens, the following workarounds can be tried:• Pass the nomodeset option on the kernel command line. This might help boot into a “fallback graphics”
mode.
• Use the Ctrl-Alt-F2 key combination to switch to VT2, which might offer a functional login prompt.

6.5

Customization

Using the shell (see Section 6.3.9.2), the installation process can be carefully customized, to fit exceptional use cases:

6.5.1

Installing an alternative init system

Debian uses systemd as its default init system. However, other init systems (such as sysvinit and OpenRC) are supported, and the easiest time to select an alternative init system is during the installation process. For detailed instructions on how to do so, please see the Init page on the Debian wiki.

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Chapter 7

Booting Into Your New Debian System
7.1

The Moment of TruthYour system’s first boot on its own power is what electrical engineers call the “smoke test”.
If the system fails to start up correctly, don’t panic. If the installation was successful, chances are good that there
is only a relatively minor problem that is preventing the system from booting Debian. In most cases such problems
can be fixed without having to repeat the installation. One available option to fix boot problems is to use the installer’sbuilt-in rescue mode (see Section 8.6).
If you are new to Debian and Linux, you may need some help from more experienced users. For less common
architectures like 64-bit ARM, your best option is to ask on the debian-arm mailing list. You can also file an installation
report as described in Section 5.4.5. Please make sure that you describe your problem clearly and include any messages
that are displayed and may help others to diagnose the issue.

7.2

Mounting encrypted volumes

If you created encrypted volumes during the installation and assigned them mount points, you will be asked to enter
the passphrase for each of these volumes during the boot.
For partitions encrypted using dm-crypt you will be shown the following prompt during the boot:Starting early crypto disks... part_crypt(starting)Enter LUKS passphrase:

In the first line of the prompt, part is the name of the underlying partition, e.g. sda2 or md0. You are now probably
wondering for which volume you are actually entering the passphrase. Does it relate to your /home? Or to /var?
Of course, if you have just one encrypted volume, this is easy and you can just enter the passphrase you used whensetting up this volume. If you set up more than one encrypted volume during the installation, the notes you wrote down
as the last step in Section 6.3.4.6 come in handy. If you did not make a note of the mapping between part_cryptand the mount points before, you can still find it in /etc/crypttab and /etc/fstab of your new system.
The prompt may look somewhat different when an encrypted root file system is mounted. This depends on which
initramfs generator was used to generate the initrd used to boot the system. The example below is for an initrd
generated using initramfs-tools:
Begin: Mounting root file system... ...
Begin: Running /scripts/local-top ...
Enter LUKS passphrase:

No characters (even asterisks) will be shown while entering the passphrase. If you enter the wrong passphrase,
you have two more tries to correct it. After the third try the boot process will skip this volume and continue to mountthe next filesystem. Please see Section 7.2.1 for further information.
After entering all passphrases the boot should continue as usual.

7.2.1

Troubleshooting

If some of the encrypted volumes could not be mounted because a wrong passphrase was entered, you will have tomount them manually after the boot. There are several cases.

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CHAPTER 7. BOOTING INTO YOUR NEW DEBIAN …

7.3. LOG IN• The first case concerns the root partition. When it is not mounted correctly, the boot process will halt and you
will have to reboot the computer to try again.
• The easiest case is for encrypted volumes holding data like /home or /srv. You can simply mount them
manually after the boot.
However for dm-crypt this is a bit tricky. First you need to register the volumes with device mapper by running:# /etc/init.d/cryptdisks startThis will scan all volumes mentioned in /etc/crypttab and will create appropriate devices under the /dev
directory after entering the correct passphrases. (Already registered volumes will be skipped, so you can repeat
this command several times without worrying.) After successful registration you can simply mount the volumes
the usual way:
# mount /mount_point• If any volume holding noncritical system files could not be mounted (/usr or /var), the system should stillboot and you should be able to mount the volumes manually like in the previous case. However, you will alsoneed to (re)start any services usually running in your default runlevel because it is very likely that they were notstarted. The easiest way is to just reboot the computer.

7.3

Log InOnce your system boots, you’ll be presented with the login prompt. Log in using the personal login and password you
selected during the installation process. Your system is now ready for use.
If you are a new user, you may want to explore the documentation which is already installed on your system as
you start to use it. There are currently several documentation systems, work is proceeding on integrating the different
types of documentation. Here are a few starting points.
Documentation accompanying programs you have installed can be found in /usr/share/doc/, under a subdirectory named after the program (or, more precise, the Debian package that contains the program). However,more extensive documentation is often packaged separately in special documentation packages that are mostly not installed by default. For example, documentation about the package management tool apt can be found in the packages
apt-doc or apt-howto.
In addition, there are some special folders within the /usr/share/doc/ hierarchy. Linux HOWTOs are
installed in .gz (compressed) format, in /usr/share/doc/HOWTO/en-txt/. After installing dhelp, you willfind a browsable index of documentation in /usr/share/doc/HTML/index.html.
One easy way to view these documents using a text based browser is to enter the following commands:$ cd /usr/share/doc/$ w3m .

The dot after the w3m command tells it to show the contents of the current directory.
If you have a graphical desktop environment installed, you can also use its web browser. Start the web browser
from the application menu and enter /usr/share/doc/ in the address bar.
You can also type info command or man command to see documentation on most commands available at thecommand prompt. Typing help will display help on shell commands. And typing a command followed by --help
will usually display a short summary of the command’s usage. If a command’s results scroll past the top of the screen,type | more after the command to cause the results to pause before scrolling past the top of the screen. To see a listof all commands available which begin with a certain letter, type the letter and then two tabs.

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Chapter 8

Next Steps and Where to Go From Here
8.1

Shutting down the system

To shut down a running Debian GNU/Linux system, you must not reboot with the reset switch on the front or backof your computer, or just turn off the computer. Debian GNU/Linux should be shut down in a controlled manner,otherwise files might get lost and/or disk damage might occur. If you run a desktop environment, there is usually an
option to “log out” available from the application menu that allows you to shutdown (or reboot) the system.
Alternatively you can press the key combination Ctrl-Alt-Del . If the key combinations do not work, a last option
is to log in as root and type the necessary commands. Use reboot to reboot the system. Use halt to halt the system
without powering it off ¹. To power off the machine, use poweroff or shutdown -h now. The systemd init systemprovides additional commands that perform the same functions; for example systemctl reboot or systemctl poweroff.

8.2

Orienting Yourself to Debian

Debian is a little different from other distributions. Even if you’re familiar with Linux in other distributions, there arethings you should know about Debian to help you to keep your system in a good, clean state. This chapter contains
material to help you get oriented; it is not intended to be a tutorial for how to use Debian, but just a very brief glimpseof the system for the very rushed.

8.2.1

Debian Packaging System

The most important concept to grasp is the Debian packaging system. In essence, large parts of your system should
be considered under the control of the packaging system. These include:• /usr (excluding /usr/local)• /var (you could make /var/local and be safe in there)• /bin• /sbin• /libFor instance, if you replace /usr/bin/perl, that will work, but then if you upgrade your perl package, the file
you put there will be replaced. Experts can get around this by putting packages on “hold” in aptitude.
One of the best installation methods is apt. You can use the command line version of apt as well as tools like
aptitude or synaptic (which are just graphical frontends for apt). Note that apt will also let you merge main, contrib,
non-free, and non-free-firmware so you can have restricted packages (strictly speaking not belonging to Debian) as
well as packages from Debian GNU/Linux at the same time.
¹Under the SysV init system halt had the same effect as poweroff, but with systemd as init system (the default since jessie) their effects aredifferent.

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8.2.2

8.3. FURTHER READING AND INFORMATION

Additional Software Available for DebianThere are official and unofficial software repositories that are not enabled in the default Debian install. These containsoftware which many find important and expect to have. Information on these additional repositories can be found on
the Debian Wiki page titled The Software Available for Debian’s Stable Release.

8.2.3

Application Version Management

Alternative versions of applications are managed by update-alternatives. If you are maintaining multiple versions ofyour applications, read the update-alternatives man page.

8.2.4

Cron Job Management

Any jobs under the purview of the system administrator should be in /etc, since they are configuration files. If you
have a root cron job for daily, weekly, or monthly runs, put them in /etc/cron.{daily,weekly,monthly}.
These are invoked from /etc/crontab, and will run in alphabetic order, which serializes them.
On the other hand, if you have a cron job that (a) needs to run as a special user, or (b) needs to run at a special timeor frequency, you can use either /etc/crontab, or, better yet, /etc/cron.d/whatever. These particular
files also have an extra field that allows you to stipulate the user account under which the cron job runs.
In either case, you just edit the files and cron will notice them automatically. There is no need to run a special
command. For more information see cron(8), crontab(5), and /usr/share/doc/cron/README.Debian.

8.3

Further Reading and Information

The Debian web site contains a large quantity of documentation about Debian. In particular, see the Debian GNU/Linux FAQ and the Debian Reference. An index of more Debian documentation is available from the Debian Documentation Project. The Debian community is self-supporting; to subscribe to one or more of the Debian mailinglists, see the Mail List Subscription page. Last, but not least, the Debian Mailing List Archives contain a wealth of
information on Debian.
If you need information about a particular program, you should first try man program , or info program .
There is lots of useful documentation in /usr/share/doc as well. In particular, /usr/share/doc/
HOWTO and /usr/share/doc/FAQ contain lots of interesting information. To submit bugs, look at /usr/
share/doc/debian/bug*. To read about Debian-specific issues for particular programs, look at /usr/share/doc/(package name)/README.Debian.
A general source of information on GNU/Linux is the Linux Documentation Project. There you will find the
HOWTOs and pointers to other very valuable information on parts of a GNU/Linux system.
Linux is an implementation of Unix. The Linux Documentation Project (LDP) collects a number of HOWTOs
and online books relating to Linux.
If you are new to Unix, you probably should go out and buy some books and do some reading. This list of Unix
FAQs contains a number of UseNet documents which provide a nice historical reference.

8.4

Setting Up Your System To Use E-Mail

Today, email is an important part of many people’s life. As there are many options as to how to set it up, and as having
it set up correctly is important for some Debian utilities, we will try to cover the basics in this section.
There are three main functions that make up an e-mail system. First there is the Mail User Agent (MUA) which isthe program a user actually uses to compose and read mails. Then there is the Mail Transfer Agent (MTA) that takes
care of transferring messages from one computer to another. And last there is the Mail Delivery Agent (MDA) thattakes care of delivering incoming mail to the user’s inbox.
These three functions can be performed by separate programs, but they can also be combined in one or two
programs. It is also possible to have different programs handle these functions for different types of mail.
On Linux and Unix systems mutt is historically a very popular MUA. Like most traditional Linux programs it is
text based. It is often used in combination with exim or sendmail as MTA and procmail as MDA.
With the increasing popularity of graphical desktop systems, the use of graphical e-mail programs like GNOME’s
evolution, KDE’s kmail or Mozilla’s thunderbird has becoming more popular. These programs combine the functionof a MUA, MTA and MDA, but can — and often are — also be used in combination with the traditional Linux tools.

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8.4.1

8.4. SETTING UP YOUR SYSTEM TO USE E-MAIL

Default E-Mail Configuration

Even if you are planning to use a graphical mail program, it would be useful, to have a traditional MTA/MDA installed
and correctly set up on your Debian GNU/Linux system. Reason is that various utilities running on the system² cansend important notices by e-mail to inform the system administrator of (potential) problems or changes.
For this you can install exim4 and mutt with apt install exim4 mutt. exim4 is a combination MTA/MDA
that is relatively small but very flexible. By default it will be configured to only handle e-mail local to the system itself
and e-mails addressed to the system administrator (root account) will be delivered to the regular user account createdduring the installation³.
When system e-mails are delivered they are added to a file in /var/mail/account_name. The e-mails canbe read using mutt.

8.4.2

Sending E-Mails Outside The System

As mentioned earlier, the installed Debian system is only set up to handle e-mail local to the system, not for sending
mail to others nor for receiving mail from others.
If you would like exim4 to handle external e-mail, please refer to the next subsection for the basic available
configuration options. Make sure to test that mail can be sent and received correctly.
If you intend to use a graphical mail program and use a mail server of your Internet Service Provider (ISP) or yourcompany, there is not really any need to configure exim4 for handling external e-mail. Just configure your favorite
graphical mail program to use the correct servers to send and receive e-mail (how is outside the scope of this manual).
However, in that case you may need to configure individual utilities to correctly send e-mails. One such utility isreportbug, a program that facilitates submitting bug reports against Debian packages. By default it expects to be able
to use exim4 to submit bug reports.
To correctly set up reportbug to use an external mail server, please run the command reportbug --configure
and answer “no” to the question if an MTA is available. You will then be asked for the SMTP server to be used forsubmitting bug reports.

8.4.3

Configuring the Exim4 Mail Transport Agent

If you would like your system to also handle external e-mail, you will need to reconfigure the exim4 package⁴:# dpkg-reconfigure exim4-config

After entering that command (as root), you will be asked if you want split the configuration into small files. If you
are unsure, select the default option.
Next you will be presented with several common mail scenarios. Choose the one that most closely resembles yourneeds.
internet site Your system is connected to a network and your mail is sent and received directly using SMTP. On thefollowing screens you will be asked a few basic questions, like your machine’s mail name, or a list of domains
for which you accept or relay mail.
mail sent by smarthost In this scenario your outgoing mail is forwarded to another machine, called a “smarthost”,
which takes care of sending the message on to its destination. The smarthost also usually stores incoming mailaddressed to your computer, so you don’t need to be permanently online. That also means you have to download
your mail from the smarthost via programs like fetchmail.
In a lot of cases the smarthost will be your ISP’s mail server, which makes this option very suitable for dial-up
users. It can also be a company mail server, or even another system on your own network.
mail sent by smarthost; no local mail This option is basically the same as the previous one except that the system
will not be set up to handle mail for a local e-mail domain. Mail on the system itself (e.g. for the systemadministrator) will still be handled.
local delivery only This is the option your system is configured for by default.
²Examples are: cron, quota, logcheck, aide, …
³The forwarding of mail for root to the regular user account is configured in /etc/aliases. If no regular user account was created, themail will of course be delivered to the root account itself.
⁴You can of course also remove exim4 and replace it with an alternative MTA/MDA.

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8.5. COMPILING A NEW KERNEL

no configuration at this time Choose this if you are absolutely convinced you know what you are doing. This will
leave you with an unconfigured mail system — until you configure it, you won’t be able to send or receive any
mail and you may miss some important messages from your system utilities.
If none of these scenarios suits your needs, or if you need a finer grained setup, you will need to edit configuration
files under the /etc/exim4 directory after the installation is complete. More information about exim4 may befound under /usr/share/doc/exim4; the file README.Debian.gz has further details about configuringexim4 and explains where to find additional documentation.
Note that sending mail directly to the Internet when you don’t have an official domain name, can result in yourmail being rejected because of anti-spam measures on receiving servers. Using your ISP’s mail server is preferred. If
you still do want to send out mail directly, you may want to use a different e-mail address than is generated by default.
If you use exim4 as your MTA, this is possible by adding an entry in /etc/email-addresses.

8.5

Compiling a New Kernel

Why would someone want to compile a new kernel? It is most probably not necessary since the default kernel shippedwith Debian handles almost all configurations.
If you want to compile your own kernel nevertheless, this is of course possible and we recommend the use of the“make deb-pkg” target. For more information read the Debian Linux Kernel Handbook.

8.6

Recovering a Broken System

Sometimes, things go wrong, and the system you’ve carefully installed is no longer bootable. Perhaps the boot loader
configuration broke while trying out a change, or perhaps a new kernel you installed won’t boot, or perhaps cosmic
rays hit your disk and flipped a bit in /sbin/init. Regardless of the cause, you’ll need to have a system to workfrom while you fix it, and rescue mode can be useful for this.
To access rescue mode, select rescue from the boot menu, type rescue at the boot: prompt, or boot withthe rescue/enable=true boot parameter. You’ll be shown the first few screens of the installer, with a note in
the corner of the display to indicate that this is rescue mode, not a full installation. Don’t worry, your system is notabout to be overwritten! Rescue mode simply takes advantage of the hardware detection facilities available in the
installer to ensure that your disks, network devices, and so on are available to you while repairing your system.
Instead of the partitioning tool, you should now be presented with a list of the partitions on your system, and asked
to select one of them. Normally, you should select the partition containing the root file system that you need to repair.
You may select partitions on RAID and LVM devices as well as those created directly on disks.
If possible, the installer will now present you with a shell prompt in the file system you selected, which you can
use to perform any necessary repairs.
If the installer cannot run a usable shell in the root file system you selected, perhaps because the file system iscorrupt, then it will issue a warning and offer to give you a shell in the installer environment instead. You may nothave as many tools available in this environment, but they will often be enough to repair your system anyway. The
root file system you selected will be mounted on the /target directory.
In either case, after you exit the shell, the system will reboot.
Finally, note that repairing broken systems can be difficult, and this manual does not attempt to go into all thethings that might have gone wrong or how to fix them. If you have problems, consult an expert.

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Appendix A

Installation Howto
This document describes how to install Debian GNU/Linux bookworm for the 64-bit ARM (“arm64”) with the newdebian-installer. It is a quick walkthrough of the installation process which should contain all the information
you will need for most installs. When more information can be useful, we will link to more detailed explanations inother parts of this document.

A.1 Preliminaries
If you encounter bugs during your install, please refer to Section 5.4.5 for instructions on how to report them. If
you have questions which cannot be answered by this document, please direct them to the debian-boot mailing list
(debian-boot@lists.debian.org) or ask on IRC (#debian-boot on the OFTC network).

A.2 Booting the installer
The debian-cd team provides builds of installation images using debian-installer on the Debian CD/DVD
page. For more information on where to get installation images, see Section 4.1.
Some installation methods require other images than those for optical media. Section 4.2.1 explains how to findimages on Debian mirrors.
The subsections below will give the details about which images you should get for each possible means of installation.

A.2.1

Optical disc

The netinst CD image is a popular image which can be used to install bookworm with the debian-installer.
This installation method is intended to boot from the image and install additional packages over a network; hence thename “netinst”. The image has the software components needed to run the installer and the base packages to provide
a minimal bookworm system. If you’d rather, you can get a full size CD/DVD image which will not need the network
to install. You only need the first image of such set.
Download whichever type you prefer and burn it to an optical disc.

A.2.2

USB memory stick

It’s also possible to install from removable USB storage devices. For example a USB keychain can make a handy
Debian install medium that you can take with you anywhere.
The easiest way to prepare your USB memory stick is to download any Debian CD or DVD image that will fit on
it, and write the image directly to the memory stick. Of course this will destroy anything already on the stick. This
works because Debian CD/DVD images are “isohybrid” images that can boot both from optical and USB drives.
There are other, more flexible ways to set up a memory stick to use the debian-installer, and it’s possible to get it
to work with smaller memory sticks. For details, see Section 4.3.

A.2.3

Booting from network

It’s also possible to boot debian-installer completely from the net. The various methods to netboot dependon your architecture and netboot setup. The files in netboot/ can be used to netboot debian-installer.
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APPENDIX A. INSTALLATION HOWTO

A.2.4

A.3. INSTALLATION

Booting from hard disk

It’s possible to boot the installer using no removable media, but just an existing hard disk, which can have a different
OS on it. Download hd-media/initrd.gz, hd-media/vmlinuz, and a Debian CD/DVD image to the toplevel directory of the hard disk. Make sure that the image has a filename ending in .iso. Now it’s just a matter ofbooting linux with the initrd.

A.3 Installation
Once the installer starts, you will be greeted with an initial screen. Press Enter to boot, or read the instructions forother boot methods and parameters (see Section 5.3).
After a while you will be asked to select your language. Use the arrow keys to pick a language and press Enterto continue. Next you’ll be asked to select your country, with the choices including countries where your language isspoken. If it’s not on the short list, a list of all the countries in the world is available.
You may be asked to confirm your keyboard layout. Choose the default unless you know better.
Now sit back while debian-installer detects some of your hardware, and loads the rest of the installation image.
Next the installer will try to detect your network hardware and set up networking by DHCP. If you are not on a
network or do not have DHCP, you will be given the opportunity to configure the network manually.
Setting up the network is followed by the creation of user accounts. By default you are asked to provide a password
for the “root” (administrator) account and information necessary to create one regular user account. If you do not
specify a password for the “root” user, this account will be disabled but the sudo package will be installed later toenable administrative tasks to be carried out on the new system. By default, the first user created on the system willbe allowed to use the sudo command to become root.
The next step is setting up your clock and time zone. The installer will try to contact a time server on the Internet
to ensure the clock is set correctly. The time zone is based on the country selected earlier and the installer will only
ask to select one if a country has multiple zones.
Now it is time to partition your disks. First you will be given the opportunity to automatically partition either anentire drive, or available free space on a drive (see Section 6.3.4.2). This is recommended for new users or anyone ina hurry. If you do not want to autopartition, choose Manual from the menu.
On the next screen you will see your partition table, how the partitions will be formatted, and where they will bemounted. Select a partition to modify or delete it. If you did automatic partitioning, you should just be able to choose
Finish partitioning and write changes to disk from the menu to use what it set up. Remember to assign at least one
partition for swap space and to mount a partition on /. For more detailed information on how to use the partitioner,
please refer to Section 6.3.4; the appendix Appendix C has more general information about partitioning.
Now debian-installer formats your partitions and starts to install the base system, which can take a while.
That is followed by installing a kernel.
The base system that was installed earlier is a working, but very minimal installation. To make the system morefunctional the next step allows you to install additional packages by selecting tasks. Before packages can be installed
apt needs to be configured as that defines from where the packages will be retrieved. The “Standard system” task
will be selected by default and should normally be installed. Select the “Desktop environment” task if you would liketo have a graphical desktop after the installation. See Section 6.3.6.2 for additional information about this step.
The last step is to install a boot loader. If the installer detects other operating systems on your computer, it will
add them to the boot menu and let you know.
debian-installer will now tell you that the installation has finished. Remove the cdrom or other boot media
and hit Enter to reboot your machine. It should boot up into the newly installed system and allow you to log in. Thisis explained in Chapter 7.
If you need more information on the install process, see Chapter 6.

A.4 Send us an installation report
If you successfully managed an installation with debian-installer, please take time to provide us with a report.
The simplest way to do so is to install the reportbug package (apt install reportbug), configure reportbug as
explained in Section 8.4.2, and run reportbug installation-reports.
If you did not complete the install, you probably found a bug in debian-installer. To improve the installer it isnecessary that we know about them, so please take the time to report them. You can use an installation report toreport problems; if the install completely fails, see Section 5.4.4.

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A.5. AND FINALLY…

A.5 And finally…
We hope that your Debian installation is pleasant and that you find Debian useful. You might want to read Chapter 8.

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Appendix B

Automating the installation usingpreseeding
This appendix explains how to preseed answers to questions in debian-installer to automate your installation.
The configuration fragments used in this appendix are also available as an example preconfiguration file fromhttps://www.debian.org/releases/bookworm/example-preseed.txt.

B.1

Introduction

Preseeding provides a way to set answers to questions asked during the installation process, without having to manuallyenter the answers while the installation is running. This makes it possible to fully automate most types of installationand even offers some features not available during normal installations.
Preseeding is not required. If you use an empty preseed file, the installer will behave just the same way as in anormal manual installation. Each question you preseed will (if you got it right!) modify the installation in some way
from that baseline.

B.1.1

Preseeding methods

There are three methods that can be used for preseeding: initrd, file and network. Initrd preseeding will work with any
installation method and supports preseeding of more things, but it requires the most preparation. File and network
preseeding each can be used with different installation methods.
The following table shows which preseeding methods can be used with which installation methods.
Installation method
CD/DVD/USB
netboot
hd-media (including
usb-stick)

initrd
yes
yes

file
yes
no

network
yes¹
yes

yes

yes

yes¹

An important difference between the preseeding methods is the point at which the preconfiguration file is loaded
and processed. For initrd preseeding this is right at the start of the installation, before the first question is evenasked. Preseeding from the kernel command line happens just after. It is thus possible to override configuration
set in the initrd by editing the kernel command line (either in the bootloader configuration or manually at boot time
for bootloaders that allow it). For file preseeding this is after the installation image has been loaded. For network
preseeding it is only after the network has been configured.

¹but only if you have network access, and set preseed/url appropriately

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APPENDIX B. AUTOMATING THE INSTALLATION …

B.2. USING PRESEEDING

IMPORTANT
Obviously, any questions that have been processed before the preconfiguration file
is loaded cannot be preseeded (this will include questions that are only displayed
at medium or low priority, like the first hardware detection run). A not so convenient
way to avoid these questions from being asked is to preseed them through the bootparameters, as described in Section B.2.2.
In order to easily avoid the questions that would normally appear before the preseeding occurs, you can start the installer in “auto” mode. This delays questions
that would normally be asked too early for preseeding (i.e. language, country andkeyboard selection) until after the network comes up, thus allowing them to be preseeded. It also runs the installation at critical priority, which avoids many unimportant questions. See Section B.2.3 for details.

B.1.2

Limitations

Although most questions used by debian-installer can be preseeded using this method, there are some notable
exceptions. You must (re)partition an entire disk or use available free space on a disk; it is not possible to use existing
partitions.

B.2

Using preseeding

You will first need to create a preconfiguration file and place it in the location from where you want to use it. Creating
the preconfiguration file is covered later in this appendix. Putting it in the correct location is fairly straightforward for
network preseeding or if you want to read the file off a usb-stick. If you want to include the file in an installation ISO
image, you will have to remaster the image. How to get the preconfiguration file included in the initrd is outside thescope of this document; please consult the developers’ documentation for debian-installer.
An example preconfiguration file that you can use as basis for your own preconfiguration file is available fromhttps://www.debian.org/releases/bookworm/example-preseed.txt. This file is based on theconfiguration fragments included in this appendix.

B.2.1

Loading the preconfiguration fileIf you are using initrd preseeding, you only have to make sure a file named preseed.cfg is included in the root
directory of the initrd. The installer will automatically check if this file is present and load it.
For the other preseeding methods you need to tell the installer what file to use when you boot it. This is normallydone by passing the kernel a boot parameter, either manually at boot time or by editing the bootloader configuration
file (e.g. syslinux.cfg) and adding the parameter to the end of the append line(s) for the kernel.
If you do specify the preconfiguration file in the bootloader configuration, you might change the configuration so
you don’t need to hit enter to boot the installer. For syslinux this means setting the timeout to 1 in syslinux.cfg.
To make sure the installer gets the right preconfiguration file, you can optionally specify a checksum for the file.
Currently this needs to be a md5sum, and if specified it must match the preconfiguration file or the installer will refuse
to use it.
Boot parameters to specify:- if you’re netbooting:preseed/url=http://host/path/to/preseed.cfg
preseed/url/checksum=5da499872becccfeda2c4872f9171c3d- orpreseed/url=tftp://host/path/to/preseed.cfg
preseed/url/checksum=5da499872becccfeda2c4872f9171c3d- if you’re booting a remastered installation image:preseed/file=/cdrom/preseed.cfg
preseed/file/checksum=5da499872becccfeda2c4872f9171c3d- if you’re installing from USB media (put the preconfiguration file in the

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toplevel directory of the USB stick):preseed/file=/hd-media/preseed.cfg
preseed/file/checksum=5da499872becccfeda2c4872f9171c3d

Note that preseed/url can be shortened to just url, preseed/file to just file and preseed/file/
checksum to just preseed-md5 when they are passed as boot parameters.

B.2.2

Using boot parameters to preseed questions

If a preconfiguration file cannot be used to preseed some steps, the install can still be fully automated, since you canpass preseed values on the command line when booting the installer.
Boot parameters can also be used if you do not really want to use preseeding, but just want to provide an answer
for a specific question. Some examples where this can be useful are documented elsewhere in this manual.
To set a value to be used inside debian-installer, just pass path/to/variable=value for any of thepreseed variables listed in the examples in this appendix. If a value is to be used to configure packages for the target
system, you will need to prepend the owner² of the variable as in owner:path/to/variable=value. If you don’t
specify the owner, the value for the variable will not be copied to the debconf database in the target system and thus
remain unused during the configuration of the relevant package.
Normally, preseeding a question in this way will mean that the question will not be asked. To set a specific default
value for a question, but still have the question asked, use “?=” instead of “=” as operator. See also Section B.5.2.
Note that some variables that are frequently set at the boot prompt have a shorter alias. If an alias is available, it
is used in the examples in this appendix instead of the full variable. The preseed/url variable for example has
been aliased as url. Another example is the tasks alias, which translates to tasksel:tasksel/first.
A “---” in the boot options has special meaning. Kernel parameters that appear after the last “---” may be copied
into the bootloader configuration for the installed system (if supported by the installer for the bootloader). The installer
will automatically filter out any options (like preconfiguration options) that it recognizes.

NOTE
Current linux kernels (2.6.9 and later) accept a maximum of 32 command line options and 32 environment options, including any options added by default for the
installer. If these numbers are exceeded, the kernel will panic (crash). (For earlier
kernels, these numbers were lower.)
For most installations some of the default options in your bootloader configuration file, like vga=normal, may
be safely removed which may allow you to add more options for preseeding.

NOTE
It may not always be possible to specify values with spaces for boot parameters,even if you delimit them with quotes.

B.2.3

Auto mode

There are several features of Debian Installer that combine to allow fairly simple command lines at the boot prompt
to result in arbitrarily complex customized automatic installs.
This is enabled by using the Automated install boot choice, also called auto for some architectures orboot methods. In this section, auto is thus not a parameter, it means selecting that boot choice, and appending thefollowing boot parameters on the boot prompt.
To illustrate this, here are some examples that can be used at the boot prompt:²The owner of a debconf variable (or template) is normally the name of the package that contains the corresponding debconf template. For
variables used in the installer itself the owner is “d-i”. Templates and variables can have more than one owner which helps to determine whether
they can be removed from the debconf database if the package is purged.

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auto url=autoserverThis relies on there being a DHCP server that will get the machine to the point where autoserver can be resolved
by DNS, perhaps after adding the local domain if that was provided by DHCP. If this was done at a site where thedomain is example.com, and they have a reasonably sane DHCP setup, it would result in the preseed file being
retrieved from http://autoserver.example.com/d-i/bookworm/./preseed.cfg.
The last part of that url (d-i/bookworm/./preseed.cfg) is taken from auto-install/defaultroot.
By default this includes the directory bookworm to allow future versions to specify their own codename and let people migrate forwards in a controlled manner. The /./ bit is used to indicate a root, relative to which subsequent paths
can be anchored (for use in preseed/include and preseed/run). This allows files to be specified either as full URLs,
paths starting with / that are thus anchored, or even paths relative to the location where the last preseed file was found.
This can be used to construct more portable scripts where an entire hierarchy of scripts can be moved to a new location
without breaking it, for example copying the files onto a USB stick when they started out on a web server. In thisexample, if the preseed file sets preseed/run to /scripts/late_command.sh then the file will be fetchedfrom http://autoserver.example.com/d-i/bookworm/./scripts/late_command.sh.
If there is no local DHCP or DNS infrastructure, or if you do not want to use the default path to preseed.cfg,
you can still use an explicit url, and if you don’t use the /./ element it will be anchored to the start of the path (i.e.
the third / in the URL). Here is an example that requires minimal support from the local network infrastructure:
auto url=http://192.168.1.2/path/to/mypreseed.file

The way this works is that:• if the URL is missing a protocol, http is assumed,• if the hostname section contains no periods, it has the domain derived from DHCP appended to it, and• if there’s no /’s after the hostname, then the default path is added.
In addition to specifying the url, you can also specify settings that do not directly affect the behavior of debian-installer
itself, but can be passed through to scripts specified using preseed/run in the loaded preseed file. At present, theonly example of this is auto-install/classes, which has an alias classes. This can be used thus:
auto url=example.com classes=class_A;class_B

The classes could for example denote the type of system to be installed, or the localization to be used.
It is of course possible to extend this concept, and if you do, it is reasonable to use the auto-install namespace forthis. So one might have something like auto-install/style which is then used in your scripts. If you feel theneed to do this, please mention it on the debian-boot@lists.debian.org mailing list so that we can avoid namespace
conflicts, and perhaps add an alias for the parameter for you.
The auto boot choice is not yet defined on all arches. The same effect may be achieved by simply adding thetwo parameters auto=true priority=critical to the kernel command line. The auto kernel parameteris an alias for auto-install/enable and setting it to true delays the locale and keyboard questions until after
there has been a chance to preseed them, while priority is an alias for debconf/priority and setting it tocritical stops any questions with a lower priority from being asked.
Additional options that may be of interest while attempting to automate an install while using DHCP are: interface=auto
netcfg/dhcp_timeout=60 which makes the machine choose the first viable NIC and be more patient about
getting a reply to its DHCP query.

TIP
An extensive example of how to use this framework, including example scripts andclasses, can be found on the website of its developer. The examples available
there also show many other nice effects that can be achieved by creative use of
preconfiguration.

B.2.4

Aliases useful with preseeding

The following aliases can be useful when using (auto mode) preseeding. Note that these are simply short aliases forquestion names, and you always need to specify a value as well: for example, auto=true or interface=eth0.

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priorityfb
autoclasses
file
url
theme
languagecountry
localekeymapmodulesfirmwareinterfacedomainhostname
protocolsuite
recommends
tasks
desktoppreseed-md5

B.2.5

debconf/priority
debian-installer/framebuffer
auto-install/enableauto-install/classes
preseed/file
preseed/url
debian-installer/theme
debian-installer/language
debian-installer/country
debian-installer/locale
keyboard-configuration/xkb-keymap
anna/choose_modules
hw-detect/firmware-lookup
netcfg/choose_interface
netcfg/get_domain
netcfg/get_hostname
mirror/protocol
mirror/suitebase-installer/install-recommends
tasksel:tasksel/firsttasksel:tasksel/desktop
preseed/file/checksum

Examples of boot prompt preseeding

Here are some examples of how the boot prompt might look like (you will need to adapt this to your needs).
# To set French as language and France as country:/install.amd/vmlinuz vga=788 initrd=/install.amd/gtk/initrd.gz language=fr ←country=FR --- quiet# To set English as language and Germany as country, and use a German keyboard ←layout:/install.amd/vmlinuz vga=788 initrd=/install.amd/gtk/initrd.gz language=en ←country=DE locale=en_US.UTF-8 keymap=de --- quiet# To install the MATE desktop:/install.amd/vmlinuz vga=788 initrd=/install.amd/gtk/initrd.gz desktop=mate- ←desktop --- quiet# To install the web-server task:/install.amd/vmlinuz initrd=/install.amd/initrd.gz tasksel:tasksel/first=web- ←server ---B.2.6

Using a DHCP server to specify preconfiguration files

It’s also possible to use DHCP to specify a preconfiguration file to download from the network. DHCP allows specifying a filename. Normally this is a file to netboot, but if it appears to be an URL then installation media that support
network preseeding will download the file from the URL and use it as a preconfiguration file. Here is an example of
how to set it up in the dhcpd.conf for version 3 of the ISC DHCP server (the isc-dhcp-server Debian package).
if substring (option vendor-class-identifier, 0, 3) = ”d-i” {filename ”http://host/preseed.cfg”;}

Note that the above example limits this filename to DHCP clients that identify themselves as “d-i”, so it will notaffect regular DHCP clients, but only the installer. You can also put the text in a stanza for only one particular host to
avoid preseeding all installs on your network.
A good way to use the DHCP preseeding is to only preseed values specific to your network, such as the Debianmirror to use. This way installs on your network will automatically get a good mirror selected, but the rest of theinstallation can be performed interactively. Using DHCP preseeding to fully automate Debian installs should only bedone with care.

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B.3

B.3. CREATING A PRECONFIGURATION FILE

Creating a preconfiguration file

The preconfiguration file is in the format used by the debconf-set-selections command. The general format of a line
in a preconfiguration file is:<owner> <question name> <question type> <value>

The file should start with #_preseed_V1
There are a few rules to keep in mind when writing a preconfiguration file.
• Put only a single space or tab between type and value: any additional whitespace will be interpreted as belonging
to the value.
• A line can be split into multiple lines by appending a backslash (“\”) as the line continuation character. A goodplace to split a line is after the question name; a bad place is between type and value. Split lines will be joined
into a single line with all leading/trailing whitespace condensed to a single space.
• For debconf variables (templates) used only in the installer itself, the owner should be set to “d-i”; to preseedvariables used in the installed system, the name of the package that contains the corresponding debconf templateshould be used. Only variables that have their owner set to something other than “d-i” will be propagated to thedebconf database for the installed system.
• Most questions need to be preseeded using the values valid in English and not the translated values. However,there are some questions (for example in partman) where the translated values need to be used.
• Some questions take a code as value instead of the English text that is shown during installation.
• Start with #_preseed_V1• A comment consists of a line which starts with a hash character (“#”) and extends up to the length of that line.
The easiest way to create a preconfiguration file is to use the example file linked in Section B.4 as basis and workfrom there.
An alternative method is to do a manual installation and then, after rebooting, use the debconf-get-selections
from the debconf-utils package to dump both the debconf database and the installer’s cdebconf database to asingle file:$ echo ”#_preseed_V1” > file$ debconf-get-selections --installer >> file$ debconf-get-selections >> file

However, a file generated in this manner will have some items that should not be preseeded, and the example fileis a better starting place for most users.

NOTE
This method relies on the fact that, at the end of the installation, the installer’s
cdebconf database is saved to the installed system in /var/log/installer/
cdebconf. However, because the database may contain sensitive information, by
default the files are only readable by root.
The directory /var/log/installer and all files in it will be deleted from yoursystem if you purge the package installation-report.
To check possible values for questions, you can use nano to examine the files in /var/lib/cdebconf while
an installation is in progress. View templates.dat for the raw templates and questions.dat for the current
values and for the values assigned to variables.
To check if the format of your preconfiguration file is valid before performing an install, you can use the command
debconf-set-selections -c preseed.cfg .

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B.4

B.4. CONTENTS OF THE PRECONFIGURATION …

Contents of the preconfiguration file (for bookworm)

The configuration fragments used in this appendix are also available as an example preconfiguration file from https://www.debian.org/releases/bookworm/example-preseed.txt.
Note that this example is based on an installation for the Intel x86 architecture. If you are installing a different
architecture, some of the examples (like keyboard selection and bootloader installation) may not be relevant and willneed to be replaced by debconf settings appropriate for your architecture.
Details on how the different Debian Installer components actually work can be found in Section 6.3.

B.4.1

Localization

During a normal install the questions about localization are asked first, so these values can only be preseeded via the initrd or kernel boot parameter methods. Auto mode (Section B.2.3) includes the setting of auto-install/enable=true(normally via the auto preseed alias). This delays the asking of the localisation questions, so that they can be preseeded by any method.
The locale can be used to specify both language and country and can be any combination of a language supported
by debian-installer and a recognized country. If the combination does not form a valid locale, the installer
will automatically select a locale that is valid for the selected language. To specify the locale as a boot parameter, use
locale=en_US.
Although this method is very easy to use, it does not allow preseeding of all possible combinations of language,
country and locale³. So alternatively the values can be preseeded individually. Language and country can also be
specified as boot parameters.
# Preseeding only locale sets language, country and locale.
d-i debian-installer/locale string en_US# The values can also be preseeded individually for greater flexibility.
#d-i debian-installer/language string en#d-i debian-installer/country string NL#d-i debian-installer/locale string en_GB.UTF-8# Optionally specify additional locales to be generated.
#d-i localechooser/supported-locales multiselect en_US.UTF-8, nl_NL.UTF-8

Keyboard configuration consists of selecting a keymap and (for non-latin keymaps) a toggle key to switch between
the non-latin keymap and the US keymap. Only basic keymap variants are available during installation. Advanced
variants are available only in the installed system, through dpkg-reconfigure keyboard-configuration.
# Keyboard selection.
d-i keyboard-configuration/xkb-keymap select us# d-i keyboard-configuration/toggle select No toggling

To skip keyboard configuration, preseed keymap with skip-config. This will result in the kernel keymap
remaining active.

B.4.2

Network configuration

Of course, preseeding the network configuration won’t work if you’re loading your preconfiguration file from the
network. But it’s great when you’re booting from optical disc or USB stick. If you are loading preconfiguration files
from the network, you can pass network config parameters by using kernel boot parameters.
If you need to pick a particular interface when netbooting before loading a preconfiguration file from the network,
use a boot parameter such as interface=eth1.
Although preseeding the network configuration is normally not possible when using network preseeding (using“preseed/url”), you can use the following hack to work around that, for example if you’d like to set a static address
for the network interface. The hack is to force the network configuration to run again after the preconfiguration filehas been loaded by creating a “preseed/run” script containing the following commands:
kill-all-dhcp; netcfg

The following debconf variables are relevant for network configuration.
³Preseeding locale to en_NL would for example result in en_US.UTF-8 as default locale for the installed system. If e.g. en_GB.UTF-8
is preferred instead, the values will need to be preseeded individually.

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# Disable network configuration entirely. This is useful for cdrom# installations on non-networked devices where the network questions,# warning and long timeouts are a nuisance.
#d-i netcfg/enable boolean false# netcfg will choose an interface that has link if possible. This makes it# skip displaying a list if there is more than one interface.
d-i netcfg/choose_interface select auto
# To pick a particular interface instead:#d-i netcfg/choose_interface select eth1
# To set a different link detection timeout (default is 3 seconds).
# Values are interpreted as seconds.
#d-i netcfg/link_wait_timeout string 10# If you have a slow dhcp server and the installer times out waiting for# it, this might be useful.
#d-i netcfg/dhcp_timeout string 60#d-i netcfg/dhcpv6_timeout string 60# Automatic network configuration is the default.
# If you prefer to configure the network manually, uncomment this line and# the static network configuration below.
#d-i netcfg/disable_autoconfig boolean true
# If you want the preconfiguration file to work on systems both with and# without a dhcp server, uncomment these lines and the static network# configuration below.
#d-i netcfg/dhcp_failed note
#d-i netcfg/dhcp_options select Configure network manually# Static network configuration.
## IPv4 example#d-i netcfg/get_ipaddress string 192.168.1.42#d-i netcfg/get_netmask string 255.255.255.0#d-i netcfg/get_gateway string 192.168.1.1#d-i netcfg/get_nameservers string 192.168.1.1#d-i netcfg/confirm_static boolean true#
# IPv6 example#d-i netcfg/get_ipaddress string fc00::2#d-i netcfg/get_netmask string ffff:ffff:ffff:ffff::#d-i netcfg/get_gateway string fc00::1#d-i netcfg/get_nameservers string fc00::1#d-i netcfg/confirm_static boolean true
# Any hostname and domain names assigned from dhcp take precedence over# values set here. However, setting the values still prevents the questions# from being shown, even if values come from dhcp.
d-i netcfg/get_hostname string unassigned-hostname
d-i netcfg/get_domain string unassigned-domain# If you want to force a hostname, regardless of what either the DHCP
# server returns or what the reverse DNS entry for the IP is, uncomment# and adjust the following line.
#d-i netcfg/hostname string somehost# Disable that annoying WEP key dialog.
d-i netcfg/wireless_wep string# The wacky dhcp hostname that some ISPs use as a password of sorts.
#d-i netcfg/dhcp_hostname string radish

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# If you want to completely disable firmware lookup (i.e. not use firmware# files or packages that might be available on installation images):#d-i hw-detect/firmware-lookup string never# If non-free firmware is needed for the network or other hardware, you can# configure the installer to always try to load it, without prompting. Or# change to false to disable asking.
#d-i hw-detect/load_firmware boolean true

Please note that netcfg will automatically determine the netmask if netcfg/get_netmask is not preseeded.
In this case, the variable has to be marked as seen for automatic installations. Similarly, netcfg will choose anappropriate address if netcfg/get_gateway is not set. As a special case, you can set netcfg/get_gateway
to “none” to specify that no gateway should be used.

B.4.3

Network console# Use the following settings if you wish to make use of the network-console# component for remote installation over SSH. This only makes sense if you# intend to perform the remainder of the installation manually.
#d-i anna/choose_modules string network-console#d-i network-console/authorized_keys_url string http://10.0.0.1/openssh-key#d-i network-console/password password r00tme#d-i network-console/password-again password r00tme

More information related to network-console can be found in Section 6.3.10.

B.4.4

Mirror settings

Depending on the installation method you use, a mirror may be used to download additional components of theinstaller, to install the base system, and to set up the /etc/apt/sources.list for the installed system.
The parameter mirror/suite determines the suite for the installed system.
The parameter mirror/udeb/suite determines the suite for additional components for the installer. It isonly useful to set this if components are actually downloaded over the network and should match the suite that wasused to build the initrd for the installation method used for the installation. Normally the installer will automaticallyuse the correct value and there should be no need to set this.
# Mirror protocol:# If you select ftp, the mirror/country string does not need to be set.
# Default value for the mirror protocol: http.
#d-i mirror/protocol string ftp
d-i mirror/country string manuald-i mirror/http/hostname string http.us.debian.org
d-i mirror/http/directory string /debiand-i mirror/http/proxy string# Suite to install.
#d-i mirror/suite string testing# Suite to use for loading installer components (optional).
#d-i mirror/udeb/suite string testing

B.4.5

Account setup

The password for the root account and name and password for a first regular user’s account can be preseeded. For the
passwords you can use either clear text values or crypt(3) hashes.

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WARNINGBe aware that preseeding passwords is not completely secure as everyone with access to the preconfiguration file will have the knowledge of these passwords. Storing hashed passwords is considered secure unless a weak hashing algorithm like
DES or MD5 is used which allow for bruteforce attacks. Recommended password
hashing algorithms are SHA-256 and SHA512.

# Skip creation of a root account (normal user account will be able to# use sudo).
#d-i passwd/root-login boolean false# Alternatively, to skip creation of a normal user account.
#d-i passwd/make-user boolean false# Root password, either in clear text
#d-i passwd/root-password password r00tme#d-i passwd/root-password-again password r00tme# or encrypted using a crypt(3) hash.
#d-i passwd/root-password-crypted password [crypt(3) hash]# To create a normal user account.
#d-i passwd/user-fullname string Debian User#d-i passwd/username string debian# Normal user’s password, either in clear text
#d-i passwd/user-password password insecure#d-i passwd/user-password-again password insecure# or encrypted using a crypt(3) hash.
#d-i passwd/user-password-crypted password [crypt(3) hash]# Create the first user with the specified UID instead of the default.
#d-i passwd/user-uid string 1010
# The user account will be added to some standard initial groups. To# override that, use this.
#d-i passwd/user-default-groups string audio cdrom video

The passwd/root-password-crypted and passwd/user-password-crypted variables can also
be preseeded with “!” as their value. In that case, the corresponding account is disabled. This may be convenient for
the root account, provided of course that an alternative method is set up to allow administrative activities or root login(for instance by using SSH key authentication or sudo).
The following command (available from the whois package) can be used to generate a SHA-512 based crypt(3)hash for a password:
mkpasswd -m sha-512

B.4.6

Clock and time zone setup# Controls whether or not the hardware clock is set to UTC.
d-i clock-setup/utc boolean true
# You may set this to any valid setting for $TZ; see the contents of# /usr/share/zoneinfo/ for valid values.
d-i time/zone string US/Eastern# Controls whether to use NTP to set the clock during the install
d-i clock-setup/ntp boolean true
# NTP server to use. The default is almost always fine here.
#d-i clock-setup/ntp-server string ntp.example.com

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B.4.7

B.4. CONTENTS OF THE PRECONFIGURATION …

Partitioning

Using preseeding to partition the harddisk is limited to what is supported by partman-auto. You can choose topartition either existing free space on a disk or a whole disk. The layout of the disk can be determined by using apredefined recipe, a custom recipe from a recipe file or a recipe included in the preconfiguration file.
Preseeding of advanced partition setups using RAID, LVM and encryption is supported, but not with the full
flexibility possible when partitioning during a non-preseeded install.
The examples below only provide basic information on the use of recipes. For detailed information see the files
partman-auto-recipe.txt and partman-auto-raid-recipe.txt included in the debian-installer
package. Both files are also available from the debian-installer source repository. Note that the supported
functionality may change between releases.

WARNING
The identification of disks is dependent on the order in which their drivers areloaded. If there are multiple disks in the system, make very sure the correct one
will be selected before using preseeding.

B.4.7.1

Partitioning example# If the system has free space you can choose to only partition that space.
# This is only honoured if partman-auto/method (below) is not set.
#d-i partman-auto/init_automatically_partition select biggest_free# Alternatively, you may specify a disk to partition. If the system has only
# one disk the installer will default to using that, but otherwise the device# name must be given in traditional, non-devfs format (so e.g. /dev/sda# and not e.g. /dev/discs/disc0/disc).
# For example, to use the first SCSI/SATA hard disk:#d-i partman-auto/disk string /dev/sda# In addition, you’ll need to specify the method to use.
# The presently available methods are:# - regular: use the usual partition types for your architecture# - lvm:use LVM to partition the disk
# - crypto: use LVM within an encrypted partition
d-i partman-auto/method string lvm# You can define the amount of space that will be used for the LVM volume# group. It can either be a size with its unit (eg. 20 GB), a percentage of# free space or the ’max’ keyword.
d-i partman-auto-lvm/guided_size string max# If one of the disks that are going to be automatically partitioned# contains an old LVM configuration, the user will normally receive a# warning. This can be preseeded away...
d-i partman-lvm/device_remove_lvm boolean true
# The same applies to pre-existing software RAID array:d-i partman-md/device_remove_md boolean true
# And the same goes for the confirmation to write the lvm partitions.
d-i partman-lvm/confirm boolean true
d-i partman-lvm/confirm_nooverwrite boolean true
# You can choose one of the three predefined partitioning recipes:# - atomic: all files in one partition# - home:
separate /home partition# - multi: separate /home, /var, and /tmp partitions
d-i partman-auto/choose_recipe select atomic# Or provide a recipe of your own...

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# If you have a way to get a recipe file into the d-i environment, you can# just point at it.
#d-i partman-auto/expert_recipe_file string /hd-media/recipe# If not, you can put an entire recipe into the preconfiguration file in one# (logical) line. This example creates a small /boot partition, suitable# swap, and uses the rest of the space for the root partition:#d-i partman-auto/expert_recipe string\#boot-root ::\#40 50 100 ext3\#
$primary{ } $bootable{ }\#method{ format } format{ }\#use_filesystem{ } filesystem{ ext3 }\#mountpoint{ /boot }
\
#
.
\
#
500 10000 1000000000 ext3\#
method{ format } format{ }\#use_filesystem{ } filesystem{ ext3 }\#mountpoint{ / }
\
#
.
\
#
64 512 300% linux-swap\#
method{ swap } format{ }\#.
# The full recipe format is documented in the file partman-auto-recipe.txt# included in the ’debian-installer’ package or available from D-I source# repository. This also documents how to specify settings such as file# system labels, volume group names and which physical devices to include# in a volume group.
## Partitioning for EFI# If your system needs an EFI partition you could add something like# this to the recipe above, as the first element in the recipe:#
538 538 1075 free\#$iflabel{ gpt }\#$reusemethod{ }\#method{ efi }\#format{ }\#.
\## The fragment above is for the amd64 architecture; the details may be# different on other architectures. The ’partman-auto’ package in the# D-I source repository may have an example you can follow.
# This makes partman automatically partition without confirmation, provided# that you told it what to do using one of the methods above.
d-i partman-partitioning/confirm_write_new_label boolean true
d-i partman/choose_partition select finish
d-i partman/confirm boolean true
d-i partman/confirm_nooverwrite boolean true
# Force UEFI booting (’BIOS compatibility’ will be lost). Default: false.
#d-i partman-efi/non_efi_system boolean true
# Ensure the partition table is GPT - this is required for EFI#d-i partman-partitioning/choose_label select gpt#d-i partman-partitioning/default_label string gpt# When disk encryption is enabled, skip wiping the partitions beforehand.
#d-i partman-auto-crypto/erase_disks boolean false73

APPENDIX B. AUTOMATING THE INSTALLATION …

B.4.7.2

B.4. CONTENTS OF THE PRECONFIGURATION …

Partitioning using RAID

You can also use preseeding to set up partitions on software RAID arrays. Supported are RAID levels 0, 1, 5, 6 and10, creating degraded arrays and specifying spare devices.

WARNING
This type of automated partitioning is easy to get wrong. It is also functionality thatreceives relatively little testing from the developers of debian-installer. The
responsibility to get the various recipes right (so they make sense and don’t conflict)lies with the user. Check /var/log/syslog if you run into problems.

# The method should be set to ”raid”.
#d-i partman-auto/method string raid
# Specify the disks to be partitioned. They will all get the same layout,# so this will only work if the disks are the same size.
#d-i partman-auto/disk string /dev/sda /dev/sdb# Next you need to specify the physical partitions that will be used.
#d-i partman-auto/expert_recipe string \#multiraid ::\#1000 5000 4000 raid\#$primary{ } method{ raid }
\
#
.
\
#
64 512 300% raid\#
method{ raid }
\
#
.
\
#
500 10000 1000000000 raid\#
method{ raid }\#.
# Last you need to specify how the previously defined partitions will be# used in the RAID setup. Remember to use the correct partition numbers# for logical partitions. RAID levels 0, 1, 5, 6 and 10 are supported;# devices are separated using ”#”.
# Parameters are:# <raidtype> <devcount> <sparecount> <fstype> <mountpoint> \#<devices> <sparedevices>#d-i partman-auto-raid/recipe string \#1 2 0 ext3 /\#/dev/sda1#/dev/sdb1
\
#
.
\
#
1 2 0 swap \#/dev/sda5#/dev/sdb5
\
#
.
\
#
0 2 0 ext3 /home\#/dev/sda6#/dev/sdb6\#.
# For additional information see the file partman-auto-raid-recipe.txt# included in the ’debian-installer’ package or available from D-I source# repository.
# This makes partman automatically partition without confirmation.
d-i partman-md/confirm boolean true
d-i partman-partitioning/confirm_write_new_label boolean true
d-i partman/choose_partition select finish
d-i partman/confirm boolean true
d-i partman/confirm_nooverwrite boolean true74

APPENDIX B. AUTOMATING THE INSTALLATION …

B.4.7.3

B.4. CONTENTS OF THE PRECONFIGURATION …

Controlling how partitions are mounted

Normally, filesystems are mounted using a universally unique identifier (UUID) as a key; this allows them to be
mounted properly even if their device name changes. UUIDs are long and difficult to read, so, if you prefer, theinstaller can mount filesystems based on the traditional device names, or based on a label you assign. If you ask the
installer to mount by label, any filesystems without a label will be mounted using a UUID instead.
Devices with stable names, such as LVM logical volumes, will continue to use their traditional names rather than
UUIDs.

WARNING
Traditional device names may change based on the order in which the kernel discovers devices at boot, which may cause the wrong filesystem to be mounted. Similarly, labels are likely to clash if you plug in a new disk or a USB drive, and if that
happens your system’s behaviour when started will be random.

# The default is to mount by UUID, but you can also choose ”traditional” to# use traditional device names, or ”label” to try filesystem labels before# falling back to UUIDs.
#d-i partman/mount_style select uuid

B.4.8

Base system installation

There is actually not very much that can be preseeded for this stage of the installation. The only questions asked
concern the installation of the kernel.
# Configure APT to not install recommended packages by default. Use of this# option can result in an incomplete system and should only be used by very
# experienced users.
#d-i base-installer/install-recommends boolean false# The kernel image (meta) package to be installed; ”none” can be used if no# kernel is to be installed.
#d-i base-installer/kernel/image string linux-image-686

B.4.9

Apt setup

Setup of the /etc/apt/sources.list and basic configuration options is fully automated based on your installation method and answers to earlier questions. You can optionally add other (local) repositories.
# Choose, if you want to scan additional installation media# (default: false).
d-i apt-setup/cdrom/set-first boolean false# You can choose to install non-free firmware.
#d-i apt-setup/non-free-firmware boolean true
# You can choose to install non-free and contrib software.
#d-i apt-setup/non-free boolean true#d-i apt-setup/contrib boolean true
# Uncomment the following line, if you don’t want to have the sources.list# entry for a DVD/BD installation image active in the installed system# (entries for netinst or CD images will be disabled anyway, regardless of# this setting).
#d-i apt-setup/disable-cdrom-entries boolean true
# Uncomment this if you don’t want to use a network mirror.
#d-i apt-setup/use_mirror boolean false# Select which update services to use; define the mirrors to be used.
# Values shown below are the normal defaults.
#d-i apt-setup/services-select multiselect security, updates#d-i apt-setup/security_host string security.debian.org

75

APPENDIX B. AUTOMATING THE INSTALLATION …

B.4. CONTENTS OF THE PRECONFIGURATION …

# Additional repositories, local[0-9] available#d-i apt-setup/local0/repository string \#http://local.server/debian stable main#d-i apt-setup/local0/comment string local server# Enable deb-src lines#d-i apt-setup/local0/source boolean true
# URL to the public key of the local repository; you must provide a key or# apt will complain about the unauthenticated repository and so the# sources.list line will be left commented out.
#d-i apt-setup/local0/key string http://local.server/key# or one can provide it in-line by base64 encoding the contents of the# key file (with ‘base64 -w0‘) and specifying it thus:#d-i apt-setup/local0/key string base64:// ←LS0tLS1CRUdJTiBQR1AgUFVCTElDIEtFWSBCTE9DSy0tLS0tCi4uLgo=# The content of the key file is checked to see if it appears to be ASCII- ←armoured.
# If so it will be saved with an ”.asc” extension, otherwise it gets a ’.gpg’ ←extension.
# ”keybox database” format is currently not supported. (see generators/60local in ←apt-setup’s source)# By default the installer requires that repositories be authenticated# using a known gpg key. This setting can be used to disable that
# authentication. Warning: Insecure, not recommended.
#d-i debian-installer/allow_unauthenticated boolean true
# Uncomment this to add multiarch configuration for i386
#d-i apt-setup/multiarch string i386

B.4.10

Package selection

You can choose to install any combination of tasks that are available. Available tasks as of this writing include:• standard (standard tools)• desktop (graphical desktop)• gnome-desktop (Gnome desktop)• xfce-desktop (XFCE desktop)• kde-desktop (KDE Plasma desktop)• cinnamon-desktop (Cinnamon desktop)• mate-desktop (MATE desktop)• lxde-desktop (LXDE desktop)• web-server (web server)• ssh-server (SSH server)
You can also choose to install no tasks, and force the installation of a set of packages in some other way. We
recommend always including the standard task.
Or if you don’t want the tasksel dialog to be shown at all, preseed pkgsel/run_tasksel (no packages are
installed via tasksel in that case).
If you want to install some individual packages in addition to packages installed by tasks, you can use the parameter
pkgsel/include. The value of this parameter can be a list of packages separated by either commas or spaces,
which allows it to be used easily on the kernel command line as well.

76

APPENDIX B. AUTOMATING THE INSTALLATION …

B.5. ADVANCED OPTIONS#tasksel tasksel/first multiselect standard, web-server, kde-desktop# Or choose to not get the tasksel dialog displayed at all (and don’t install# any packages):#d-i pkgsel/run_tasksel boolean false# Individual additional packages to install#d-i pkgsel/include string openssh-server build-essential# Whether to upgrade packages after debootstrap.
# Allowed values: none, safe-upgrade, full-upgrade#d-i pkgsel/upgrade select none
# You can choose, if your system will report back on what software you have# installed, and what software you use. The default is not to report back,# but sending reports helps the project determine what software is most
# popular and should be included on the first CD/DVD.
#popularity-contest popularity-contest/participate boolean false

B.4.11Finishing up the installation# During installations from serial console, the regular virtual consoles# (VT1-VT6) are normally disabled in /etc/inittab. Uncomment the next
# line to prevent this.
#d-i finish-install/keep-consoles boolean true
# Avoid that last message about the install being complete.
d-i finish-install/reboot_in_progress note
# This will prevent the installer from ejecting the CD during the reboot,# which is useful in some situations.
#d-i cdrom-detect/eject boolean false# This is how to make the installer shutdown when finished, but not# reboot into the installed system.
#d-i debian-installer/exit/halt boolean true
# This will power off the machine instead of just halting it.
#d-i debian-installer/exit/poweroff boolean true

B.4.12Preseeding other packages# Depending on what software you choose to install, or if things go wrong# during the installation process, it’s possible that other questions may# be asked. You can preseed those too, of course. To get a list of every# possible question that could be asked during an install, do an# installation, and then run these commands:#
debconf-get-selections --installer > file#
debconf-get-selections >> file

B.5

Advanced options

B.5.1

Running custom commands during the installation

A very powerful and flexible option offered by the preconfiguration tools is the ability to run commands or scripts at
certain points in the installation.
When the filesystem of the target system is mounted, it is available in /target. If an installation CD is used,
when it is mounted it is available in /cdrom.

77

APPENDIX B. AUTOMATING THE INSTALLATION …

B.5. ADVANCED OPTIONS# d-i preseeding is inherently not secure. Nothing in the installer checks# for attempts at buffer overflows or other exploits of the values of a
# preconfiguration file like this one. Only use preconfiguration files from# trusted locations! To drive that home, and because it’s generally useful,# here’s a way to run any shell command you’d like inside the installer,# automatically.
# This first command is run as early as possible, just after# preseeding is read.
#d-i preseed/early_command string anna-install some-udeb# This command is run immediately before the partitioner starts. It may be# useful to apply dynamic partitioner preseeding that depends on the state# of the disks (which may not be visible when preseed/early_command runs).
#d-i partman/early_command \#string debconf-set partman-auto/disk ”$(list-devices disk | head -n1)”# This command is run just before the install finishes, but when there is# still a usable /target directory. You can chroot to /target and use it# directly, or use the apt-install and in-target commands to easily install# packages and run commands in the target system.
#d-i preseed/late_command string apt-install zsh; in-target chsh -s /bin/zsh

B.5.2

Using preseeding to change default values

It is possible to use preseeding to change the default answer for a question, but still have the question asked. To dothis the seen flag must be reset to “false” after setting the value for a question.
d-i foo/bar string value
d-i foo/bar seen false

The same effect can be achieved for all questions by setting the parameter preseed/interactive=true at theboot prompt. This can also be useful for testing or debugging your preconfiguration file.
Note that the “d-i” owner should only be used for variables used in the installer itself. For variables belonging
to packages installed on the target system, you should use the name of that package instead. See the footnote to
Section B.2.2.
If you are preseeding using boot parameters, you can make the installer ask the corresponding question by using
the “?=” operator, i.e. foo/bar?=value (or owner:foo/bar?=value). This will of course only have effectfor parameters that correspond to questions that are actually displayed during an installation and not for “internal”
parameters.
For more debugging information, use the boot parameter DEBCONF_DEBUG=5. This will cause debconf toprint much more detail about the current settings of each variable and about its progress through each package’s
installation scripts.

B.5.3

Chainloading preconfiguration files

It is possible to include other preconfiguration files from a preconfiguration file. Any settings in those files will override
pre-existing settings from files loaded earlier. This makes it possible to put, for example, general networking settings
for your location in one file and more specific settings for certain configurations in other files.
# More than one file can be listed, separated by spaces; all will be# loaded. The included files can have preseed/include directives of their# own as well. Note that if the filenames are relative, they are taken from# the same directory as the preconfiguration file that includes them.
#d-i preseed/include string x.cfg# The installer can optionally verify checksums of preconfiguration files# before using them. Currently only md5sums are supported, list the md5sums# in the same order as the list of files to include.
#d-i preseed/include/checksum string 5da499872becccfeda2c4872f9171c3d# More flexibly, this runs a shell command and if it outputs the names of# preconfiguration files, includes those files.
#d-i preseed/include_command \78

APPENDIX B. AUTOMATING THE INSTALLATION …

#

B.5. ADVANCED OPTIONS

string if [ ”‘hostname‘” = bob ]; then echo bob.cfg; fi# Most flexibly of all, this downloads a program and runs it. The program# can use commands such as debconf-set to manipulate the debconf database.
# More than one script can be listed, separated by spaces.
# Note that if the filenames are relative, they are taken from the same
# directory as the preconfiguration file that runs them.
#d-i preseed/run string foo.sh

It is also possible to chainload from the initrd or file preseeding phase, into network preseeding by setting preseed/url in the earlier files. This will cause network preseeding to be performed when the network comes up. You
need to be careful when doing this, since there will be two distinct runs at preseeding, meaning for example that you
get another chance to run the preseed/early command, the second one happening after the network comes up.

79

Appendix C

Partitioning for Debian
C.1

Deciding on Debian Partitions and Sizes

At a bare minimum, GNU/Linux needs one partition for itself. You can have a single partition containing the entire
operating system, applications, and your personal files. Most people feel that a separate swap partition is also anecessity, although it’s not strictly true. “Swap” is scratch space for an operating system, which allows the system touse disk storage as “virtual memory”. By putting swap on a separate partition, Linux can make much more efficientuse of it. It is possible to force Linux to use a regular file as swap, but it is not recommended.
Most people choose to give GNU/Linux more than the minimum number of partitions, however. There are two
reasons you might want to break up the file system into a number of smaller partitions. The first is for safety. If
something happens to corrupt the file system, generally only one partition is affected. Thus, you only have to replace(from the backups you’ve been carefully keeping) a portion of your system. At a bare minimum, you should consider
creating what is commonly called a “root partition”. This contains the most essential components of the system. If
any other partitions get corrupted, you can still boot into GNU/Linux to fix the system. This can save you the troubleof having to reinstall the system from scratch.
The second reason is generally more important in a business setting, but it really depends on your use of themachine. For example, a mail server getting spammed with e-mail can easily fill a partition. If you made /var/maila separate partition on the mail server, most of the system will remain working even if you get spammed.
The only real drawback to using more partitions is that it is often difficult to know in advance what your needs willbe. If you make a partition too small then you will either have to reinstall the system or you will be constantly moving
things around to make room in the undersized partition. On the other hand, if you make the partition too big, you will
be wasting space that could be used elsewhere. Disk space is cheap nowadays, but why throw your money away?

C.2

The Directory Tree

Debian GNU/Linux adheres to the Filesystem Hierarchy Standard for directory and file naming. This standard allows
users and software programs to predict the location of files and directories. The root level directory is represented
simply by the slash /. At the root level, all Debian systems include these directories:
Directory
bin
boot
dev
etc
home
lib
media
mnt
proc
root
run
sbin
sys
tmp

Content
Essential command binaries
Static files of the boot loader
Device files
Host-specific system configuration
User home directories
Essential shared libraries and kernel modules
Contains mount points for replaceable media
Mount point for mounting a file system temporarily
Virtual directory for system information
Home directory for the root user
Run-time variable data
Essential system binaries
Virtual directory for system information
Temporary files
80

APPENDIX C. PARTITIONING FOR DEBIAN

C.3. RECOMMENDED PARTITIONING SCHEME

Directory
usr
var
srv
opt

Content
Secondary hierarchy
Variable data
Data for services provided by the system
Add-on application software packages

The following is a list of important considerations regarding directories and partitions. Note that disk usage varies
widely given system configuration and specific usage patterns. The recommendations here are general guidelines andprovide a starting point for partitioning.
• The root partition / must always physically contain /etc, /bin, /sbin, /lib, /dev and /usr, otherwise
you won’t be able to boot. This means that you should provide at least 600–750MB of disk space for the root
partition including /usr, or 5–6GB for a workstation or a server installation.
• /var: variable data like news articles, e-mails, web sites, databases, the packaging system cache, etc. will beplaced under this directory. The size of this directory depends greatly on the usage of your system, but for mostpeople will be dictated by the package management tool’s overhead. If you are going to do a full installation ofjust about everything Debian has to offer, all in one session, setting aside 2 or 3 GB of space for /var should
be sufficient. If you are going to install in pieces (that is to say, install services and utilities, followed by text
stuff, then X, ...), you can get away with 300–500 MB. If hard drive space is at a premium and you don’t planon doing major system updates, you can get by with as little as 30 or 40 MB.
• /tmp: temporary data created by programs will most likely go in this directory. 40–100MB should usually
be enough. Some applications — including archive manipulators, CD/DVD authoring tools, and multimedia
software — may use /tmp to temporarily store image files. If you plan to use such applications, you should
adjust the space available in /tmp accordingly.
• /home: every user will put his personal data into a subdirectory of this directory. Its size depends on how
many users will be using the system and what files are to be stored in their directories. Depending on yourplanned usage you should reserve about 100MB for each user, but adapt this value to your needs. Reserve a lot
more space if you plan to save a lot of multimedia files (pictures, MP3, movies) in your home directory.

C.3

Recommended Partitioning Scheme

For new users, personal Debian boxes, home systems, and other single-user setups, a single / partition (plus swap) is
probably the easiest, simplest way to go. The recommended partition type is ext4.
For multi-user systems or systems with lots of disk space, it’s best to put /var, /tmp, and /home each on theirown partitions separate from the / partition.
You might need a separate /usr/local partition if you plan to install many programs that are not part of the
Debian distribution. If your machine will be a mail server, you might need to make /var/mail a separate partition.
If you are setting up a server with lots of user accounts, it’s generally good to have a separate, large /home partition.
In general, the partitioning situation varies from computer to computer depending on its uses.
For very complex systems, you should see the Multi Disk HOWTO. This contains in-depth information, mostly
of interest to ISPs and people setting up servers.
With respect to the issue of swap partition size, there are many views. One rule of thumb which works well is touse as much swap as you have system memory. It also shouldn’t be smaller than 512MB, in most cases. Of course,
there are exceptions to these rules.
As an example, an older home machine might have 512MB of RAM and a 20GB SATA drive on /dev/sda.
There might be a 8GB partition for another operating system on /dev/sda1, a 512MB swap partition on /dev/
sda3 and about 11.4GB on /dev/sda2 as the Linux partition.
For an idea of the space taken by tasks you might be interested in adding after your system installation is complete,
check Section D.2.

C.4

Device Names in LinuxLinux disks and partition names may be different from other operating systems. You need to know the names that
Linux uses when you create and mount partitions. Here’s the basic naming scheme:• The first hard disk detected is named /dev/sda.
81

APPENDIX C. PARTITIONING FOR DEBIAN

C.5. DEBIAN PARTITIONING PROGRAMS• The second hard disk detected is named /dev/sdb, and so on.
• The first SCSI CD-ROM is named /dev/scd0, also known as /dev/sr0.
The partitions on each disk are represented by appending a decimal number to the disk name: sda1 and sda2
represent the first and second partitions of the first SCSI disk drive in your system.
Here is a real-life example. Let’s assume you have a system with 2 SCSI disks, one at SCSI address 2 and theother at SCSI address 4. The first disk (at address 2) is then named sda, and the second sdb. If the sda drive has
3 partitions on it, these will be named sda1, sda2, and sda3. The same applies to the sdb disk and its partitions.
Note that if you have two SCSI host bus adapters (i.e., controllers), the order of the drives can get confusing. The
best solution in this case is to watch the boot messages, assuming you know the drive models and/or capacities.

C.5

Debian Partitioning Programs

Several varieties of partitioning programs have been adapted by Debian developers to work on various types of harddisks and computer architectures. Following is a list of the program(s) applicable for your architecture.
partman Recommended partitioning tool in Debian. This Swiss army knife can also resize partitions, create filesystems and assign them to the mountpoints.
fdisk The original Linux disk partitioner, good for gurus.
Be careful if you have existing FreeBSD partitions on your machine. The installation kernels include support
for these partitions, but the way that fdisk represents them (or not) can make the device names differ. See theLinux+FreeBSD HOWTO.
cfdisk A simple-to-use, full-screen disk partitioner for the rest of us.
Note that cfdisk doesn’t understand FreeBSD partitions at all, and, again, device names may differ as a result.
One of these programs will be run by default when you select Partition disks (or similar). It may be possible touse a different partitioning tool from the command line on VT2, but this is not recommended.

82

Appendix D

Random Bits
D.1

Linux Devices

In Linux various special files can be found under the directory /dev. These files are called device files and behave
unlike ordinary files. The most common types of device files are for block devices and character devices. These files
are an interface to the actual driver (part of the Linux kernel) which in turn accesses the hardware. Another, lesscommon, type of device file is the named pipe. The most important device files are listed in the tables below.
sda
sdb
sda1
sdb7

First hard disk
Second hard disk
First partition of the first hard disk
Seventh partition of the second hard disk

sr0
sr1

First CD-ROM
Second CD-ROM

ttyS0
ttyS1
psaux

Serial port 0, COM1 under MS-DOS
Serial port 1, COM2 under MS-DOS
PS/2 mouse device
Pseudo device, repeater data from GPM (mouse)
daemongpmdata

cdrom
mouse

Symbolic link to the CD-ROM drive
Symbolic link to the mouse device file

null
zero

Anything written to this device will disappear
One can endlessly read zeros out of this device

D.1.1

Setting Up Your Mouse

The mouse can be used in both the Linux console (with gpm) and the X window environment. Normally, this is a
simple matter of installing gpm and the X server itself. Both should be configured to use /dev/input/mice as
the mouse device. The correct mouse protocol is named exps2 in gpm, and ExplorerPS/2 in X. The respective
configuration files are /etc/gpm.conf and /etc/X11/xorg.conf.
Certain kernel modules must be loaded in order for your mouse to work. In most cases the correct modules areautodetected, but not always for old-style serial and bus mice¹, which are quite rare except on very old computers.
Summary of Linux kernel modules needed for different mouse types:¹Serial mice usually have a 9-hole D-shaped connector; bus mice have an 8-pin round connector, not to be confused with the 6-pin roundconnector of a PS/2 mouse or the 4-pin round connector of an ADB mouse.

83

APPENDIX D. RANDOM BITS

D.3. INSTALLING DEBIAN GNU/LINUX FROM A …

Modulepsmouseusbhidsermouse
logibmDescription
PS/2 mice (should be autodetected)
USB mice (should be autodetected)
Most serial mice
Bus mouse connected to Logitech adapter card
Bus mouse connected to ATI or Microsoft InPort
cardinport

To load a mouse driver module, you can use the modconf command (from the package with the same name) andlook in the category kernel/drivers/input/mouse.

D.2

Disk Space Needed for Tasks

A standard installation for the amd64 architecture, including all standard packages and using the default kernel,
takes up 1242MB of disk space. A minimal base installation, without the “Standard system” task selected, willtake 1012MB.

IMPORTANTIn both cases this is the actual disk space used after the installation is finished andany temporary files deleted. It also does not take into account overhead used by
the file system, for example for journal files. This means that significantly more disk
space is needed both during the installation and for normal system use.
The following table lists sizes reported by aptitude for the tasks listed in tasksel. Note that some tasks haveoverlapping constituents, so the total installed size for two tasks together may be less than the total obtained by adding
up the numbers.
By default the installer will install the GNOME desktop environment, but alternative desktop environments canbe selected either by using one of the special installation images, or by specifying the desired desktop environment
during installation (see Section 6.3.6.2).
Note that you will need to add the sizes listed in the table to the size of the standard installation when determining
the size of partitions. Most of the size listed as “Installed size” will end up in /usr and in /lib; the size listed as“Download size” is (temporarily) required in /var.
Task

Installed size (MB)

Download size (MB)Space needed to install(MB)

Desktop environment• GNOME (default)• KDE Plasma• Xfce• LXDE• MATE• Cinnamon
Web server
SSH server

3216
4584
2509
2539
2851
4676
85
2

859
1316
683
693
762
1324
19
1

4075
5900
3192
3232
3613
6000
104
3

If you install in a language other than English, tasksel may automatically install a localization task, if one isavailable for your language. Space requirements differ per language; you should allow up to 350MB in total for
download and installation.

D.3

Installing Debian GNU/Linux from a Unix/Linux System

This section explains how to install Debian GNU/Linux from an existing Unix or Linux system, without using themenu-driven installer as explained in the rest of the manual. This “cross-install” HOWTO has been requested byusers switching to Debian GNU/Linux from Red Hat, Mandriva, and SUSE. In this section some familiarity with84

APPENDIX D. RANDOM BITS

D.3. INSTALLING DEBIAN GNU/LINUX FROM A …

entering *nix commands and navigating the file system is assumed. In this section, $ symbolizes a command to beentered in the user’s current system, while # refers to a command entered in the Debian chroot.
Once you’ve got the new Debian system configured to your preference, you can migrate your existing user data (ifany) to it, and keep on rolling. This is therefore a “zero downtime” Debian GNU/Linux install. It’s also a clever way
for dealing with hardware that otherwise doesn’t play friendly with various boot or installation media.

NOTE
As this is a mostly manual procedure, you should bear in mind that you will need to
do a lot of basic configuration of the system yourself, which will also require more
knowledge of Debian and of Linux in general than performing a regular installation.
You cannot expect this procedure to result in a system that is identical to a systemfrom a regular installation. You should also keep in mind that this procedure only
gives the basic steps to set up a system. Additional installation and/or configuration
steps may be needed.

D.3.1

Getting Started

With your current *nix partitioning tools, repartition the hard drive as needed, creating at least one filesystem plus
swap. You need around 1012MB of space available for a console only install, or about 2539MB if you plan to install
X (more if you intend to install desktop environments like GNOME or KDE Plasma).
Next, create file systems on the partitions. For example, to create an ext3 file system on partition /dev/sda6(that’s our example root partition):# mke2fs -j /dev/sda6

To create an ext2 file system instead, omit -j.
Initialize and activate swap (substitute the partition number for your intended Debian swap partition):# mkswap /dev/sda5# sync# swapon /dev/sda5

Mount one partition as /mnt/debinst (the installation point, to be the root (/) filesystem on your new system).
The mount point name is strictly arbitrary, it is referenced later below.
# mkdir /mnt/debinst# mount /dev/sda6 /mnt/debinst

NOTE
If you want to have parts of the filesystem (e.g. /usr) mounted on separate partitions,
you will need to create and mount these directories manually before proceeding with
the next stage.

D.3.2

Install debootstrap

The utility used by the Debian installer, and recognized as the official way to install a Debian base system, is debootstrap. It uses wget and ar, but otherwise depends only on /bin/sh and basic Unix/Linux tools². Install wget andar if they aren’t already on your current system, then download and install debootstrap.
Or, you can use the following procedure to install it manually. Make a work folder for extracting the .deb into:²These include the GNU core utilities and commands like sed, grep, tar and gzip.

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# mkdir work
# cd work

The debootstrap binary is located in the Debian archive (be sure to select the proper file for your architecture).
Download the debootstrap .deb from the pool, copy the package to the work folder, and extract the files from it. You
will need to have root privileges to install the files.
# ar -x debootstrap_0.X.X_all.deb# cd /# zcat /full-path-to-work/work/data.tar.gz | tar xv

D.3.3

Run debootstrap

debootstrap can download the needed files directly from the archive when you run it. You can substitute any Debianarchive mirror for http.us.debian.org/debian in the command example below, preferably a mirror close
to you network-wise. Mirrors are listed at http://www.debian.org/mirror/list.
If you have a bookworm Debian GNU/Linux installation image mounted at /cdrom, you could substitute a file
URL instead of the http URL: file:/cdrom/debian/
Substitute one of the following for ARCH in the debootstrap command: amd64, arm64, armel, armhf, i386,
mips64el, mipsel, ppc64el, s390x.
# /usr/sbin/debootstrap --arch ARCH bookworm \/mnt/debinst http://ftp.us.debian.org/debian

If the target architecture is different than the host, you should add the --foreign option.

D.3.4

Configure The Base System

Now you’ve got a real Debian system, though rather lean, on disk. chroot into it:# LANG=C.UTF-8 chroot /mnt/debinst /bin/bash

If the target architecture is different from the host, you will need to first copy qemu-user-static to the new host:# cp /usr/bin/qemu-ARCH-static /mnt/debinst/usr/bin# LANG=C.UTF-8 chroot /mnt/debinst qemu-ARCH-static /bin/bash

After chrooting you may need to set the terminal definition to be compatible with the Debian base system, for example:# export TERM=xterm-color

Depending on the value of TERM, you may have to install the ncurses-term package to get support for it.
If the target architecture is different from the host, you need to finish the multi-stage boot strap:/debootstrap/debootstrap --second-stage

D.3.4.1

Create device files

At this point /dev/ only contains very basic device files. For the next steps of the installation additional device files
may be needed. There are different ways to go about this and which method you should use depends on the hostsystem you are using for the installation, on whether you intend to use a modular kernel or not, and on whether you
intend to use dynamic (e.g. using udev) or static device files for the new system.
A few of the available options are:• install the makedev package, and create a default set of static device files using (after chrooting)# apt install makedev# mount none /proc -t proc
# cd /dev# MAKEDEV generic• manually create only specific device files using MAKEDEV• bind mount /dev from your host system on top of /dev in the target system; note that the postinst scripts of somepackages may try to create device files, so this option should only be used with care
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Mount Partitions

You need to create /etc/fstab.
# editor /etc/fstab

Here is a sample you can modify to suit:# /etc/fstab: static file system information.
## file system
mount point
type
options/dev/XXX/
ext3
defaults/dev/XXX/boot
ext3
ro,nosuid,nodev

dump pass01
02/dev/XXX
proc

none
/proc

swap
proc

0
0

0
0

/dev/cdrom/media/cdrom

iso9660 noauto,ro,user,exec

00/dev/XXX/dev/XXX/dev/XXX/dev/XXX

/tmp
/var
/usr
/home

ext3
ext3
ext3
ext3

0
0
0
0

2
2
2
2

sw
defaults

rw,nosuid,nodev
rw,nosuid,nodev
rw,nodev
rw,nosuid,nodev

Use mount -a to mount all the file systems you have specified in your /etc/fstab, or, to mount file systems
individually, use:
# mount /path# e.g.: mount /usr

Current Debian systems have mountpoints for removable media under /media, but keep compatibility symlinks in/. Create these as as needed, for example:# cd /media# mkdir cdrom0# ln -s cdrom0 cdrom# cd /# ln -s media/cdrom

You can mount the proc file system multiple times and to arbitrary locations, though /proc is customary. If you
didn’t use mount -a, be sure to mount proc before continuing:# mount -t proc proc /proc

The command ls /proc should now show a non-empty directory. Should this fail, you may be able to mountproc from outside the chroot:# mount -t proc proc /mnt/debinst/proc

D.3.4.3

Setting Timezone

Setting the third line of the file /etc/adjtime to “UTC” or “LOCAL” determines whether the system will interpretthe hardware clock as being set to UTC respective local time. The following command allows you to set that.
# editor /etc/adjtime

Here is a sample:
0.0 0 0.0
0UTC

The following command allows you to choose your timezone.
# dpkg-reconfigure tzdata

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Configure Networking

To configure networking, edit /etc/network/interfaces, /etc/resolv.conf, /etc/hostname and/etc/hosts.
# editor /etc/network/interfaces

Here are some simple examples from /usr/share/doc/ifupdown/examples:####################################################################### /etc/network/interfaces -- configuration file for ifup(8), ifdown(8)# See the interfaces(5) manpage for information on what options are# available.
####################################################################### The loopback interface isn’t really required any longer, but can be used
# if needed.
## auto lo# iface lo inet loopback# To use dhcp:## auto eth0
# iface eth0 inet dhcp
# An example static IP setup: (network, broadcast and gateway are optional)## auto eth0
# iface eth0 inet static#
address 192.168.0.42#
network 192.168.0.0#
netmask 255.255.255.0#
broadcast 192.168.0.255#
gateway 192.168.0.1

Enter your nameserver(s) and search directives in /etc/resolv.conf:# editor /etc/resolv.conf

A simple example /etc/resolv.conf:
search example.com
nameserver 10.1.1.36
nameserver 192.168.9.100

Enter your system’s host name (2 to 63 characters):# echo DebianHostName > /etc/hostname

And a basic /etc/hosts with IPv6 support:
127.0.0.1 localhost
127.0.1.1 DebianHostName# The following lines are desirable for IPv6 capable hosts::1
ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts

If you have multiple network cards, you should arrange the names of driver modules in the /etc/modules file into
the desired order. Then during boot, each card will be associated with the interface name (eth0, eth1, etc.) that you
expect.

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D.3. INSTALLING DEBIAN GNU/LINUX FROM A …

Configure Apt

Debootstrap will have created a very basic /etc/apt/sources.list that will allow installing additional packages. However, you may want to add some additional sources, for example for source packages and security updates:
deb-src http://ftp.us.debian.org/debian bookworm maindeb http://security.debian.org/ bookworm-security maindeb-src http://security.debian.org/ bookworm-security main

Make sure to run apt update after you have made changes to the sources list.
D.3.4.6

Configure Locales and Keyboard

To configure your locale settings to use a language other than English, install the locales support package andconfigure it. Currently the use of UTF-8 locales is recommended.
# apt install locales# dpkg-reconfigure locales

To configure your keyboard (if needed):# apt install console-setup# dpkg-reconfigure keyboard-configuration

Note that the keyboard cannot be set while in the chroot, but will be configured for the next reboot.

D.3.5

Install a Kernel

If you intend to boot this system, you probably want a Linux kernel and a boot loader. Identify available pre-packaged
kernels with:# apt search linux-image

Then install the kernel package of your choice using its package name.
# apt install linux-image-arch-etc

D.3.6

Set up the Boot Loader

To make your Debian GNU/Linux system bootable, set up your boot loader to load the installed kernel with your new
root partition. Note that debootstrap does not install a boot loader, but you can use apt inside your Debian chroot to
do so.
Note that this assumes that a /dev/sda device file has been created. There are alternative methods to install
grub2, but those are outside the scope of this appendix.

D.3.7

Remote access: Installing SSH and setting up accessIn case you can login to the system via console, you can skip this section. If the system should be accessible via the
network later on, you need to install SSH and set up access.
# apt install ssh

Root login with password is disabled by default, so setting up access can be done by setting a password and re-enableroot login with password:# passwd# editor /etc/ssh/sshd_config

This is the option to be enabled:
PermitRootLogin yes

Access can also be set up by adding an ssh key to the root account:89

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# mkdir /root/.ssh# cat << EOF > /root/.ssh/authorized_keys
ssh-rsa ....
EOF

Lastly, access can be set up by adding a non-root user and setting a password:# adduser joe# passwd joe

D.3.8

Finishing touches

As mentioned earlier, the installed system will be very basic. If you would like to make the system a bit more mature,
there is an easy method to install all packages with “standard” priority:# tasksel install standard

Of course, you can also just use apt to install packages individually.
After the installation there will be a lot of downloaded packages in /var/cache/apt/archives/. You canfree up some diskspace by running:# apt clean

D.4

Installing Debian GNU/Linux using PPP over Ethernet (PPPoE)

In some countries PPP over Ethernet (PPPoE) is a common protocol for broadband (ADSL or cable) connections to
an Internet Service Provider. Setting up a network connection using PPPoE is not supported by default in the installer,
but can be made to work very simply. This section explains how.
The PPPoE connection set up during the installation will also be available after the reboot into the installed system(see Chapter 7).
To have the option of setting up and using PPPoE during the installation, you will need to install using one of the
CD-ROM/DVD images that are available. It is not supported for other installation methods (e.g. netboot).
Installing over PPPoE is mostly the same as any other installation. The following steps explain the differences.
• Boot the installer with the boot parameter modules=ppp-udeb. This will ensure the component responsible
for the setup of PPPoE (ppp-udeb) will be loaded and run automatically.
• Follow the regular initial steps of the installation (language, country and keyboard selection; the loading ofadditional installer components³).
• The next step is the detection of network hardware, in order to identify any Ethernet cards present in the system.
• After this the actual setup of PPPoE is started. The installer will probe all the detected Ethernet interfaces in
an attempt to find a PPPoE concentrator (a type of server which handles PPPoE connections).
It is possible that the concentrator will not to be found at the first attempt. This can happen occasionally on
slow or loaded networks or with faulty servers. In most cases a second attempt to detect the concentrator will
be successful; to retry, select Configure and start a PPPoE connection from the main menu of the installer.
• After a concentrator is found, the user will be prompted to type the login information (the PPPoE username
and password).
• At this point the installer will use the provided information to establish the PPPoE connection. If the correct
information was provided, the PPPoE connection should be configured and the installer should be able to use
it to connect to the Internet and retrieve packages over it (if needed). If the login information is not correct orsome error appears, the installer will stop, but the configuration can be attempted again by selecting the menu
entry Configure and start a PPPoE connection.
³The ppp-udeb component is loaded as one of the additional components in this step. If you want to install at medium or low priority(expert mode), you can also manually select the ppp-udeb instead of entering the “modules” parameter at the boot prompt.

90Appendix E

Administrivia
E.1 About This Document
This manual was created for Sarge’s debian-installer, based on the Woody installation manual for boot-floppies, which
was based on earlier Debian installation manuals, and on the Progeny distribution manual which was released under
GPL in 2003.
This document is written in DocBook XML. Output formats are generated by various programs using informationfrom the docbook-xml and docbook-xsl packages.
In order to increase the maintainability of this document, we use a number of XML features, such as entities andprofiling attributes. These play a role akin to variables and conditionals in programming languages. The XML source
to this document contains information for each different architecture — profiling attributes are used to isolate certain
bits of text as architecture-specific.

E.2 Contributing to This Document
If you have problems or suggestions regarding this document, you should probably submit them as a bug report against
the package installation-guide. See the reportbug package or read the online documentation of the
Debian Bug Tracking System. It would be nice if you could check the open bugs against installation-guide to see
whether your problem has already been reported. If so, you can supply additional corroboration or helpful information
to XXXX @bugs.debian.org, where XXXX is the number for the already-reported bug.
Better yet, get a copy of the DocBook source for this document, and produce patches against it. The DocBook
source can be found at the installation-guide project on salsa. If you’re not familiar with DocBook, don’t worry: there
is a simple cheatsheet in the manuals directory that will get you started. It’s like html, but oriented towards the meaningof the text rather than the presentation. Patches submitted to the debian-boot mailing list (see below) are welcomed.
For instructions on how to check out the sources via git, see README from the source root directory.
Please do not contact the authors of this document directly. There is also a discussion list for debian-installer,
which includes discussions of this manual. The mailing list is debian-boot@lists.debian.org. Instructions for subscribing to this list can be found at the Debian Mailing List Subscription page; or you can browse the Debian Mailing List
Archives online.

E.3 Major Contributions
This document was originally written by Bruce Perens, Sven Rudolph, Igor Grobman, James Treacy, and Adam Di
Carlo. Sebastian Ley wrote the Installation Howto.
Miroslav Kuře has documented a lot of the new functionality in Sarge’s debian-installer. Frans Pop was the main
editor and release manager during the Etch, Lenny and Squeeze releases.
Many, many Debian users and developers contributed to this document. Particular note must be made of Michael
Schmitz (m68k support), Frank Neumann (original author of the Amiga install manual), Arto Astala, Eric Delaunay/Ben Collins (SPARC information), Tapio Lehtonen, and Stéphane Bortzmeyer for numerous edits and text. We
have to thank Pascal Le Bail for useful information about booting from USB memory sticks.
Extremely helpful text and information was found in Jim Mintha’s HOWTO for network booting (no URL available), the Debian FAQ, the Linux/m68k FAQ, the Linux for SPARC Processors FAQ, the Linux/Alpha FAQ, amongst
others. The maintainers of these freely available and rich sources of information must be recognized.

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E.4. TRADEMARK ACKNOWLEDGEMENT

The section on chrooted installations in this manual (Section D.3) was derived in part from documents copyright
Karsten M. Self.

E.4 Trademark Acknowledgement
All trademarks are property of their respective trademark owners.

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Appendix F

GNU General Public License
Version 2, June 1991
Copyright (C) 1989, 1991 Free Software Foundation, Inc.
51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
Everyone is permitted to copy and distribute verbatim copiesof this license document, but changing it is not allowed.

F.1

Preamble

The licenses for most software are designed to take away your freedom to share and change it. By contrast, the gnu
General Public License is intended to guarantee your freedom to share and change free software — to make surethe software is free for all its users. This General Public License applies to most of the Free Software Foundation’s
software and to any other program whose authors commit to using it. (Some other Free Software Foundation software
is covered by the gnu Library General Public License instead.) You can apply it to your programs, too.
When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are designed
to make sure that you have the freedom to distribute copies of free software (and charge for this service if you wish),that you receive source code or can get it if you want it, that you can change the software or use pieces of it in new
free programs; and that you know you can do these things.
To protect your rights, we need to make restrictions that forbid anyone to deny you these rights or to ask you
to surrender the rights. These restrictions translate to certain responsibilities for you if you distribute copies of thesoftware, or if you modify it.
For example, if you distribute copies of such a program, whether gratis or for a fee, you must give the recipients
all the rights that you have. You must make sure that they, too, receive or can get the source code. And you mustshow them these terms so they know their rights.
We protect your rights with two steps: (1) copyright the software, and (2) offer you this license which gives you
legal permission to copy, distribute and/or modify the software.
Also, for each author’s protection and ours, we want to make certain that everyone understands that there is no
warranty for this free software. If the software is modified by someone else and passed on, we want its recipients toknow that what they have is not the original, so that any problems introduced by others will not reflect on the original
authors’ reputations.
Finally, any free program is threatened constantly by software patents. We wish to avoid the danger that redistributors of a free program will individually obtain patent licenses, in effect making the program proprietary. To prevent
this, we have made it clear that any patent must be licensed for everyone’s free use or not licensed at all.
The precise terms and conditions for copying, distribution and modification follow.

F.2

GNU GENERAL PUBLIC LICENSETERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
0. This License applies to any program or other work which contains a notice placed by the copyright holder
saying it may be distributed under the terms of this General Public License. The “Program”, below, refers to any suchprogram or work, and a “work based on the Program” means either the Program or any derivative work under copyright
law: that is to say, a work containing the Program or a portion of it, either verbatim or with modifications and/or
93

APPENDIX F. GNU GENERAL PUBLIC LICENSE

F.2. GNU GENERAL PUBLIC LICENSE

translated into another language. (Hereinafter, translation is included without limitation in the term “modification”.)
Each licensee is addressed as “you”.
Activities other than copying, distribution and modification are not covered by this License; they are outside its
scope. The act of running the Program is not restricted, and the output from the Program is covered only if its contents
constitute a work based on the Program (independent of having been made by running the Program). Whether thatis true depends on what the Program does.
1. You may copy and distribute verbatim copies of the Program’s source code as you receive it, in any medium,provided that you conspicuously and appropriately publish on each copy an appropriate copyright notice and disclaimer
of warranty; keep intact all the notices that refer to this License and to the absence of any warranty; and give any otherrecipients of the Program a copy of this License along with the Program.
You may charge a fee for the physical act of transferring a copy, and you may at your option offer warranty
protection in exchange for a fee.
2. You may modify your copy or copies of the Program or any portion of it, thus forming a work based on the
Program, and copy and distribute such modifications or work under the terms of Section 1 above, provided that you
also meet all of these conditions:a. You must cause the modified files to carry prominent notices stating that you changed the files and the date ofany change.
b. You must cause any work that you distribute or publish, that in whole or in part contains or is derived from theProgram or any part thereof, to be licensed as a whole at no charge to all third parties under the terms of thisLicense.
c. If the modified program normally reads commands interactively when run, you must cause it, when started
running for such interactive use in the most ordinary way, to print or display an announcement including anappropriate copyright notice and a notice that there is no warranty (or else, saying that you provide a warranty)
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These requirements apply to the modified work as a whole. If identifiable sections of that work are not derived
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3. You may copy and distribute the Program (or a work based on it, under Section 2) in object code or executableform under the terms of Sections 1 and 2 above provided that you also do one of the following:a. Accompany it with the complete corresponding machine-readable source code, which must be distributed under
the terms of Sections 1 and 2 above on a medium customarily used for software interchange; or,b. Accompany it with a written offer, valid for at least three years, to give any third party, for a charge no more thanyour cost of physically performing source distribution, a complete machine-readable copy of the corresponding
source code, to be distributed under the terms of Sections 1 and 2 above on a medium customarily used forsoftware interchange; or,c. Accompany it with the information you received as to the offer to distribute corresponding source code. (Thisalternative is allowed only for noncommercial distribution and only if you received the program in object codeor executable form with such an offer, in accord with Subsection b above.)
The source code for a work means the preferred form of the work for making modifications to it. For an executable work, complete source code means all the source code for all modules it contains, plus any associated interface
definition files, plus the scripts used to control compilation and installation of the executable. However, as a special
exception, the source code distributed need not include anything that is normally distributed (in either source or binary

94

APPENDIX F. GNU GENERAL PUBLIC LICENSE

F.2. GNU GENERAL PUBLIC LICENSEform) with the major components (compiler, kernel, and so on) of the operating system on which the executable runs,
unless that component itself accompanies the executable.
If distribution of executable or object code is made by offering access to copy from a designated place, thenoffering equivalent access to copy the source code from the same place counts as distribution of the source code, eventhough third parties are not compelled to copy the source along with the object code.
4. You may not copy, modify, sublicense, or distribute the Program except as expressly provided under thisLicense. Any attempt otherwise to copy, modify, sublicense or distribute the Program is void, and will automaticallyterminate your rights under this License. However, parties who have received copies, or rights, from you under thisLicense will not have their licenses terminated so long as such parties remain in full compliance.
5. You are not required to accept this License, since you have not signed it. However, nothing else grants you
permission to modify or distribute the Program or its derivative works. These actions are prohibited by law if you do
not accept this License. Therefore, by modifying or distributing the Program (or any work based on the Program),
you indicate your acceptance of this License to do so, and all its terms and conditions for copying, distributing or
modifying the Program or works based on it.
6. Each time you redistribute the Program (or any work based on the Program), the recipient automaticallyreceives a license from the original licensor to copy, distribute or modify the Program subject to these terms andconditions. You may not impose any further restrictions on the recipients’ exercise of the rights granted herein. You
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If any portion of this section is held invalid or unenforceable under any particular circumstance, the balance ofthe section is intended to apply and the section as a whole is intended to apply in other circumstances.
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This section is intended to make thoroughly clear what is believed to be a consequence of the rest of this License.
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excluded. In such case, this License incorporates the limitation as if written in the body of this License.
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new problems or concerns. Each version is given a distinguishing version number. If the Program specifies a version
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10. If you wish to incorporate parts of the Program into other free programs whose distribution conditions aredifferent, write to the author to ask for permission. For software which is copyrighted by the Free Software Foundation,
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NO WARRANTY
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THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE
STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM“AS IS” WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT
NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
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APPENDIX F. GNU GENERAL PUBLIC LICENSE

F.3. HOW TO APPLY THESE TERMS TO YOUR …

12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILLAND COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE
THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING
RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF
THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHERPARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
END OF TERMS AND CONDITIONS

F.3

How to Apply These Terms to Your New Programs

If you develop a new program, and you want it to be of the greatest possible use to the public, the best way to achieve
this is to make it free software which everyone can redistribute and change under these terms.
To do so, attach the following notices to the program. It is safest to attach them to the start of each source file tomost effectively convey the exclusion of warranty; and each file should have at least the “copyright” line and a pointerto where the full notice is found.
one line to give the program’s name and a brief idea of what it does.
Copyright (C) year name of author
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public Licensealong with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

Also add information on how to contact you by electronic and paper mail.
If the program is interactive, make it output a short notice like this when it starts in an interactive mode:
Gnomovision version 69, Copyright (C) year name of author
Gnomovision comes with absolutely no warranty; for details
type show w. This is free software, and you are welcome
to redistribute it under certain conditions; type show cfor details.

The hypothetical commands “show w” and “show c” should show the appropriate parts of the General Public
License. Of course, the commands you use may be called something other than “show w” and “show c”; they could
even be mouse-clicks or menu items — whatever suits your program.
You should also get your employer (if you work as a programmer) or your school, if any, to sign a “copyright
disclaimer” for the program, if necessary. Here is a sample; alter the names:
Yoyodyne, Inc., hereby disclaims all copyright interest in the
program Gnomovision (which makes passes at compilers) written
by James Hacker.
signature of Ty Coon, 1 April 1989
Ty Coon, President of Vice

This General Public License does not permit incorporating your program into proprietary programs. If yourprogram is a subroutine library, you may consider it more useful to permit linking proprietary applications with thelibrary. If this is what you want to do, use the GNU Lesser General Public License instead of this License.

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