</listitem> </itemizedlist> </para> <del> </listitem> <listitem> <para> Mount the target file system on which NixOS should be installed on <filename>/mnt</filename>, e.g. </del> <ins> </section> </section> <section xml:id="sec-installation-installing"> <title>Installing</title> <orderedlist> <listitem> <para> Mount the target file system on which NixOS should be installed on <filename>/mnt</filename>, e.g. </ins> <screen> # mount /dev/disk/by-label/nixos /mnt </screen> <del> </para> </listitem> <listitem> <variablelist> <varlistentry> <term> UEFI systems </term> <listitem> <para> Mount the boot file system on <filename>/mnt/boot</filename>, e.g. </del> <ins> </para> </listitem> <listitem> <variablelist> <varlistentry> <term> UEFI systems </term> <listitem> <para> Mount the boot file system on <filename>/mnt/boot</filename>, e.g. </ins> <screen> # mkdir -p /mnt/boot # mount /dev/disk/by-label/boot /mnt/boot </screen> <del> </para> </listitem> </varlistentry> </variablelist> </listitem> <listitem> <para> If your machine has a limited amount of memory, you may want to activate swap devices now (<command>swapon <replaceable>device</replaceable></command>). The installer (or rather, the build actions that it may spawn) may need quite a bit of RAM, depending on your configuration. </del> <ins> </para> </listitem> </varlistentry> </variablelist> </listitem> <listitem> <para> If your machine has a limited amount of memory, you may want to activate swap devices now (<command>swapon <replaceable>device</replaceable></command>). The installer (or rather, the build actions that it may spawn) may need quite a bit of RAM, depending on your configuration. </ins> <screen> # swapon /dev/sda2</screen> <del> </para> </listitem> <listitem> <para> You now need to create a file <filename>/mnt/etc/nixos/configuration.nix</filename> that specifies the intended configuration of the system. This is because NixOS has a <emphasis>declarative</emphasis> configuration model: you create or edit a description of the desired configuration of your system, and then NixOS takes care of making it happen. The syntax of the NixOS configuration file is described in <xref linkend="sec-configuration-syntax"/>, while a list of available configuration options appears in <xref </del> <ins> </para> </listitem> <listitem> <para> You now need to create a file <filename>/mnt/etc/nixos/configuration.nix</filename> that specifies the intended configuration of the system. This is because NixOS has a <emphasis>declarative</emphasis> configuration model: you create or edit a description of the desired configuration of your system, and then NixOS takes care of making it happen. The syntax of the NixOS configuration file is described in <xref linkend="sec-configuration-syntax"/>, while a list of available configuration options appears in <xref </ins> linkend="ch-options"/>. A minimal example is shown in <del> <xref </del> <ins> <xref </ins> linkend="ex-config"/>. <del> </para> <para> The command <command>nixos-generate-config</command> can generate an initial configuration file for you: </del> <ins> </para> <para> The command <command>nixos-generate-config</command> can generate an initial configuration file for you: </ins> <screen> # nixos-generate-config --root /mnt</screen> <del> You should then edit <filename>/mnt/etc/nixos/configuration.nix</filename> to suit your needs: </del> <ins> You should then edit <filename>/mnt/etc/nixos/configuration.nix</filename> to suit your needs: </ins> <screen> # nano /mnt/etc/nixos/configuration.nix </screen> <del> If you’re using the graphical ISO image, other editors may be available (such as <command>vim</command>). If you have network access, you can also install other editors — for instance, you can install Emacs by running <literal>nix-env -i emacs</literal>. </para> <variablelist> <varlistentry> <term> BIOS systems </term> <listitem> <para> You <emphasis>must</emphasis> set the option <xref linkend="opt-boot.loader.grub.device"/> to specify on which disk the GRUB boot loader is to be installed. Without it, NixOS cannot boot. </para> </listitem> </varlistentry> <varlistentry> <term> UEFI systems </term> <listitem> <para> You <emphasis>must</emphasis> set the option <xref linkend="opt-boot.loader.systemd-boot.enable"/> to <literal>true</literal>. <command>nixos-generate-config</command> should do this automatically for new configurations when booted in UEFI mode. </para> <para> You may want to look at the options starting with <option><link linkend="opt-boot.loader.efi.canTouchEfiVariables">boot.loader.efi</link></option> and <option><link linkend="opt-boot.loader.systemd-boot.enable">boot.loader.systemd</link></option> as well. </para> </listitem> </varlistentry> </variablelist> <para> If there are other operating systems running on the machine before installing NixOS, the <xref linkend="opt-boot.loader.grub.useOSProber"/> option can be set to <literal>true</literal> to automatically add them to the grub menu. </para> <para> Another critical option is <option>fileSystems</option>, specifying the file systems that need to be mounted by NixOS. However, you typically don’t need to set it yourself, because <command>nixos-generate-config</command> sets it automatically in <filename>/mnt/etc/nixos/hardware-configuration.nix</filename> from your currently mounted file systems. (The configuration file <filename>hardware-configuration.nix</filename> is included from <filename>configuration.nix</filename> and will be overwritten by future invocations of <command>nixos-generate-config</command>; thus, you generally should not modify it.) </para> <note> </del> <ins> If you’re using the graphical ISO image, other editors may be available (such as <command>vim</command>). If you have network access, you can also install other editors — for instance, you can install Emacs by running <literal>nix-env -i emacs</literal>. </para> <variablelist> <varlistentry> <term> BIOS systems </term> <listitem> <para> You <emphasis>must</emphasis> set the option <xref linkend="opt-boot.loader.grub.device"/> to specify on which disk the GRUB boot loader is to be installed. Without it, NixOS cannot boot. </para> </listitem> </varlistentry> <varlistentry> <term> UEFI systems </term> <listitem> <para> You <emphasis>must</emphasis> set the option <xref linkend="opt-boot.loader.systemd-boot.enable"/> to <literal>true</literal>. <command>nixos-generate-config</command> should do this automatically for new configurations when booted in UEFI mode. </para> <para> You may want to look at the options starting with <option><link linkend="opt-boot.loader.efi.canTouchEfiVariables">boot.loader.efi</link></option> and <option><link linkend="opt-boot.loader.systemd-boot.enable">boot.loader.systemd</link></option> as well. </para> </listitem> </varlistentry> </variablelist> </ins> <para> <del> Depending on your hardware configuration or type of file system, you may need to set the option <option>boot.initrd.kernelModules</option> to include the kernel modules that are necessary for mounting the root file system, otherwise the installed system will not be able to boot. (If this happens, boot from the CD again, mount the target file system on <filename>/mnt</filename>, fix <filename>/mnt/etc/nixos/configuration.nix</filename> and rerun <filename>nixos-install</filename>.) In most cases, <command>nixos-generate-config</command> will figure out the required modules. </del> <ins> If there are other operating systems running on the machine before installing NixOS, the <xref linkend="opt-boot.loader.grub.useOSProber"/> option can be set to <literal>true</literal> to automatically add them to the grub menu. </ins> </para> <del> </note> </listitem> <listitem> <para> Do the installation: </del> <ins> <para> Another critical option is <option>fileSystems</option>, specifying the file systems that need to be mounted by NixOS. However, you typically don’t need to set it yourself, because <command>nixos-generate-config</command> sets it automatically in <filename>/mnt/etc/nixos/hardware-configuration.nix</filename> from your currently mounted file systems. (The configuration file <filename>hardware-configuration.nix</filename> is included from <filename>configuration.nix</filename> and will be overwritten by future invocations of <command>nixos-generate-config</command>; thus, you generally should not modify it.) </para> <note> <para> Depending on your hardware configuration or type of file system, you may need to set the option <option>boot.initrd.kernelModules</option> to include the kernel modules that are necessary for mounting the root file system, otherwise the installed system will not be able to boot. (If this happens, boot from the installation media again, mount the target file system on <filename>/mnt</filename>, fix <filename>/mnt/etc/nixos/configuration.nix</filename> and rerun <filename>nixos-install</filename>.) In most cases, <command>nixos-generate-config</command> will figure out the required modules. </para> </note> </listitem> <listitem> <para> Do the installation: </ins> <screen> # nixos-install</screen> <del> Cross fingers. If this fails due to a temporary problem (such as a network issue while downloading binaries from the NixOS binary cache), you can just re-run <command>nixos-install</command>. Otherwise, fix your <filename>configuration.nix</filename> and then re-run <command>nixos-install</command>. </para> <para> As the last step, <command>nixos-install</command> will ask you to set the password for the <literal>root</literal> user, e.g. </del> <ins> Cross fingers. If this fails due to a temporary problem (such as a network issue while downloading binaries from the NixOS binary cache), you can just re-run <command>nixos-install</command>. Otherwise, fix your <filename>configuration.nix</filename> and then re-run <command>nixos-install</command>. </para> <para> As the last step, <command>nixos-install</command> will ask you to set the password for the <literal>root</literal> user, e.g. </ins> <screen> setting root password... Enter new UNIX password: *** <del> Retype new UNIX password: *** </screen> <note> <para> For unattended installations, it is possible to use <command>nixos-install --no-root-passwd</command> in order to disable the password prompt entirely. </para> </note> </para> </listitem> <listitem> <para> If everything went well: </del> <ins> Retype new UNIX password: ***</screen> <note> <para> For unattended installations, it is possible to use <command>nixos-install --no-root-passwd</command> in order to disable the password prompt entirely. </para> </note> </para> </listitem> <listitem> <para> If everything went well: </ins> <screen> <del> # reboot</screen> </para> </listitem> <listitem> <para> You should now be able to boot into the installed NixOS. The GRUB boot menu shows a list of <emphasis>available configurations</emphasis> (initially just one). Every time you change the NixOS configuration (see <link </del> <ins> # reboot</screen> </para> </listitem> <listitem> <para> You should now be able to boot into the installed NixOS. The GRUB boot menu shows a list of <emphasis>available configurations</emphasis> (initially just one). Every time you change the NixOS configuration (see <link </ins> linkend="sec-changing-config">Changing Configuration</link> <del> ), a new item is added to the menu. This allows you to easily roll back to a previous configuration if something goes wrong. </para> <para> You should log in and change the <literal>root</literal> password with <command>passwd</command>. </para> <para> You’ll probably want to create some user accounts as well, which can be done with <command>useradd</command>: </del> <ins> ), a new item is added to the menu. This allows you to easily roll back to a previous configuration if something goes wrong. </para> <para> You should log in and change the <literal>root</literal> password with <command>passwd</command>. </para> <para> You’ll probably want to create some user accounts as well, which can be done with <command>useradd</command>: </ins> <screen> $ useradd -c 'Eelco Dolstra' -m eelco $ passwd eelco</screen> <del> </para> <para> You may also want to install some software. For instance, </del> <ins> </para> <para> You may also want to install some software. For instance, </ins> <screen> $ nix-env -qa *</screen> <del> shows what packages are available, and </del> <ins> shows what packages are available, and </ins> <screen> $ nix-env -i w3m</screen> <del> install the <literal>w3m</literal> browser. </para> </listitem> </orderedlist> <para> To summarise, <xref linkend="ex-install-sequence" /> shows a typical sequence of commands for installing NixOS on an empty hard drive (here <filename>/dev/sda</filename>). <xref linkend="ex-config" </del> <ins> install the <literal>w3m</literal> browser. </para> </listitem> </orderedlist> </section> <section xml:id="sec-installation-summary"> <title>Installation summary</title> <para> To summarise, <xref linkend="ex-install-sequence" /> shows a typical sequence of commands for installing NixOS on an empty hard drive (here <filename>/dev/sda</filename>). <xref linkend="ex-config" </ins> /> shows a <del> corresponding configuration Nix expression. </para> <example xml:id='ex-install-sequence'> <title>Commands for Installing NixOS on <filename>/dev/sda</filename></title> <screen> # fdisk /dev/sda # <lineannotation>(or whatever device you want to install on)</lineannotation> -- for UEFI systems only > n      # <lineannotation>(create a new partition for /boot)</lineannotation> > 3      # <lineannotation>(make it a partition number 3)</lineannotation> >        # <lineannotation>(press enter to accept the default)</lineannotation> > +512M  # <lineannotation>(the size of the UEFI boot partition)</lineannotation> > t      # <lineannotation>(change the partition type ...)</lineannotation> > 3      # <lineannotation>(... of the boot partition ...)</lineannotation> > 1      # <lineannotation>(... to 'UEFI System')</lineannotation> -- for BIOS or UEFI systems > n      # <lineannotation>(create a new partition for /swap)</lineannotation> > 2      # <lineannotation>(make it a partition number 2)</lineannotation> >        # <lineannotation>(press enter to accept the default)</lineannotation> > +8G    # <lineannotation>(the size of the swap partition)</lineannotation> > n      # <lineannotation>(create a new partition for /)</lineannotation> > 1      # <lineannotation>(make it a partition number 1)</lineannotation> >        # <lineannotation>(press enter to accept the default)</lineannotation> >        # <lineannotation>(press enter to accept the default and use the rest of the remaining space)</lineannotation> > a      # <lineannotation>(make the partition bootable)</lineannotation> > x      # <lineannotation>(enter expert mode)</lineannotation> > f      # <lineannotation>(fix up the partition ordering)</lineannotation> > r      # <lineannotation>(exit expert mode)</lineannotation> > w      # <lineannotation>(write the partition table to disk and exit)</lineannotation> </del> <ins> corresponding configuration Nix expression. </para> <example xml:id="ex-partition-scheme-MBR"> <title>Example partition schemes for NixOS on <filename>/dev/sda</filename> (MBR)</title> <screen language="commands"> # parted /dev/sda -- mklabel msdos # parted /dev/sda -- mkpart primary linux-swap 1M 8GiB # parted /dev/sda -- mkpart primary 8GiB -1s</screen> </example> <example xml:id="ex-partition-scheme-UEFI"> <title>Example partition schemes for NixOS on <filename>/dev/sda</filename> (UEFI)</title> <screen language="commands"> # parted /dev/sda -- mklabel gpt # parted /dev/sda -- mkpart primary linux-swap 512MiB 8.5GiB # parted /dev/sda -- mkpart primary 8.5GiB -1MiB # parted /dev/sda -- mkpart ESP fat32 1M 512MiB # parted /dev/sda -- set 3 boot on</screen> </example> <example xml:id="ex-install-sequence"> <title>Commands for Installing NixOS on <filename>/dev/sda</filename></title> <para> With a partitioned disk. <screen language="commands"> </ins> # mkfs.ext4 -L nixos /dev/sda1 # mkswap -L swap /dev/sda2 # swapon /dev/sda2