GRUB Legacy

Related articles
Arch boot process
General troubleshooting#Boot problems
Kernel parameters
GRUB Legacy
is a
multiboot
boot loader previously maintained by the
GNU Project
. It was derived from
GRUB
, the
GR
and
U
nified
B
ootloader, which was originally designed and implemented by Erich Stefan Boleyn.
Briefly, the
boot loader
is the first software program that runs when a computer starts. It is responsible for loading and transferring control to the Linux kernel. The kernel, in turn, initializes the rest of the operating system.
Warning
GRUB Legacy is no longer maintained upstream and is
not officially supported
in Arch.
Note
GRUB legacy does not support
GPT
disks,
Btrfs
filesystem and
UEFI
firmwares.
Supported file systems
GRUB legacy bundles its own support for
multiple file systems
, notably
FAT32
,
ext2
,
ReiserFS
or
XFS
(although v4 only).
Warning
File systems can have new features not supported by GRUB Legacy, making them unsuitable for
/boot
unless disabling incompatible features. This can be typically worked around by using a separate
/boot partition
with a universally supported file system such as
FAT32
.
Installation
GRUB Legacy can be
installed
from the
grub-legacy
AUR
package.
Additionally, GRUB must be installed to the boot sector of a drive or partition to serve as a
boot loader
. This is covered in
#Boot loader installation
.
Configuration
The configuration file is located at
/boot/grub/menu.lst
. Edit this file to suit your needs.
timeout #
-- time to wait (in seconds) before the
default
operating system is automatically loaded.
default #
-- the default boot entry that is chosen when the
timeout
has expired.
An example configuration (with
/boot
on a separate partition) is
provided with the package
.
Finding GRUB's root
GRUB must be told where its files reside on the system, since multiple instances may exist (i.e., in multi-boot environments). GRUB files always reside under
/boot
, which may be on a dedicated partition.
Note
GRUB defines storage devices differently than conventional kernel naming does.
Hard disks are defined as
(hdX)
; this also refers to any USB storage devices.
Device and partitioning numbering begin at zero. For example, the first hard disk recognized in the BIOS will be defined as
(hd0)
. The second device will be called
(hd1)
. This also applies to partitions. So, the second partition on the first hard disk will be defined as
(hd0,1)
.
If you are unaware of the location of
/boot
, use the GRUB shell
find
command to locate the GRUB files. Enter the GRUB shell as root by:
# grub
The following example is for systems
without
a separate
/boot
partition, wherein
/boot
is merely a directory under
/
:
grub> find /boot/grub/stage1
The following example is for systems
with
a separate
/boot
partition:
grub> find /grub/stage1
GRUB will find the file, and output the location of the
stage1
file. For example:
grub> find /grub/stage1
(hd0,0)
This value should be entered on the
root
line in your configuration file. Type
quit
to exit the shell.
Dual booting with Windows
This article or section is out of date.
Reason:
The comment about removing "makeactive" is probably no longer necessary and the examples should simply remove it, since it was added
a few months after Windows 7 release
. Similarly, the information about Windows 2000 is irrelevant nowadays. (Discuss in
Talk:GRUB Legacy
)
Add the following to the end of your
/boot/grub/menu.lst
(assuming that your Windows partition is on the first partition of the first drive):
/boot/grub/menu.lst
title Windows
 rootnoverify (hd0,0)
 makeactive
 chainloader +1
Note
If you are attempting to dual-boot with Windows 7, you should comment out the line
makeactive
.
Windows 2000 and later versions do NOT need to be on the first partition to boot (contrary to popular belief). If the Windows partition changes (i.e. if you add a partition before the Windows partition), you will need to edit the Windows
boot.ini
file to reflect the change (see
this article
for details on how to do that).
If Windows is located on another hard disk, the
map
command must be used. This will make your Windows install think it is actually on the first drive. Assuming that your Windows partition is on the first partition of the second drive:
/boot/grub/menu.lst
title Windows
 map (hd0) (hd1)
 map (hd1) (hd0)
 rootnoverify (hd1,0)
 makeactive
 chainloader +1
Dual booting with GNU/Linux
This can be done the same way that an Arch Linux install is defined. For example:
/boot/grub/menu.lst
title Other Linux
root (hd0,2)
kernel
/path/to/kernel
root=/dev/sda3 ro
initrd
/path/to/initramfs
Note
There may be other options that are required, and an initial RAM disk may not be used. Examine the other distribution's
/boot/grub/menu.lst
to match boot options, or see
#chainloader and configfile
(recommended).
chainloader and configfile
To facilitate system maintenance, the
chainloader
or
configfile
command should be used to boot another Linux distribution that provides an "automagic" GRUB configuration mechanism (e.g. Debian, Ubuntu, openSUSE). This allows the distribution to manage its own
menu.lst
and boot options.
The
chainloader
command will load another boot loader (rather than a kernel image); useful if another boot loader is installed in a partition's boot sector (GRUB, for example). This allows one to install a "main" instance of GRUB to the
MBR
and distribution-specific instances of GRUB to each partition boot record (PBR).
The
configfile
command will instruct the currently running GRUB instance to load the specified configuration file. This can be used to load another distribution's
menu.lst
without a separate GRUB installation. The caveat of this approach is that other
menu.lst
may not be compatible with the installed version of GRUB; some distributions heavily patch their versions of GRUB.
For example, GRUB is to be installed to the
MBR
and some other boot loader (be it GRUB or
LILO
) is already installed to the boot sector of
(hd0,2)
.
---------------------------------------------
|   |           |           |   %           |
| M |           |           | B %           |
| B |  (hd0,0)  |  (hd0,1)  | L %  (hd0,2)  |
| R |           |           |   %           |
|   |           |           |   %           |
---------------------------------------------
  |                           ^
  |       chainloading        |
  -----------------------------
One can simply include in
menu.lst
:
title Other Linux
root (hd0,2)
chainloader +1
Or, if the boot loader on
(hd0,2)
is GRUB:
title Other Linux
root (hd0,2)
configfile /boot/grub/menu.lst
The
chainloader
command can also be used to load the MBR of a second drive:
title Other drive
rootnoverify (hd1)
chainloader +1
Dual booting with GNU/Linux (GRUB2)
If the other Linux distribution uses GRUB2 (e.g. Ubuntu 9.10+), and you installed its boot loader to its root partition, you can add an entry like this one to your
/boot/grub/menu.lst
:
/boot/grub/menu.lst
# other Linux using GRUB2
 title Ubuntu
 root (hd0,2)
 kernel /boot/grub/core.img
Selecting this entry at boot will load the other distribution's GRUB2 menu assuming that the distribution is installed on
/dev/sda3
.
Boot loader installation
Manual recovery of GRUB libs
The
*stage*
files are expected to be in
/boot/grub
, which may not be the case if the boot loader was not installed during system installation or if the partition/filesystem was damaged, accidentally deleted, etc.
Manually copy the GRUB libs like so:
# cp -a /usr/lib/grub/i386-pc/* /boot/grub
Note
Do not forget to mount the system's boot partition if your setup uses a separate one!  The above assumes that either the boot partition resides on the root filesystem or is mounted to /boot on the root file system!
General notes about boot loader installation
GRUB may be installed from a separate medium (e.g. a LiveCD), or directly from a running Arch install. GRUB is
seldom
required to be reinstalled and installation is
not
necessary when:
The configuration file is updated.
The
grub-legacy
AUR
package is updated.
Installation is
necessary
when:
A boot loader is not already installed.
Another operating system overwrites the Linux boot loader.
The boot loader fails for some unknown reason.
Before continuing, a few notes:
Be sure that your GRUB configuration is correct (
/boot/grub/menu.lst
) before proceeding. Refer to
Finding GRUB's root
to ensure your devices are defined correctly.
GRUB must be installed on the
MBR
(first sector of the hard disk), or the first partition of the first storage device to be recognized by most BIOSes. To allow individual distributions the ability to manage their own GRUB menus, multiple instances of GRUB can be used, see
#chainloader and configfile
.
Installing GRUB may need to be done from within a
chroot
ed environment (i.e. from installed environment via a separate medium) for cases like RAID configurations or if you forgot/broke your GRUB installation. You will need to
Change root
from a LiveCD or another Linux installation to do so.
First, enter the GRUB shell:
# grub
Use the
root
command with the output from the
find
command (see
#Finding GRUB's root
) to instruct GRUB which partition contains stage1 (and therefore,
/boot
):
grub> root (hd1,0)
Tip
The GRUB shell also supports tab-completion. If you type 'root (hd' then press
Tab
twice you will see the available storage devices, this can also be done for partitions. Tab-completion also works from the GRUB boot menu. If there is an error in your configuration file you can edit in the boot menu and use tab-completion to help find devices and partitions. See
#Edit GRUB entries in the boot menu
.
Installing to the MBR
The following example installs GRUB to the
MBR
of the first drive:
grub> setup (hd0)
Installing to a partition
The following example installs GRUB to the first partition of the first drive:
grub> setup (hd0,0)
After running
setup
, enter
quit
to exit the shell. If you chrooted,
exit your chroot and unmount partitions
. Now reboot to test.
Alternate method (grub-install)
Note
This procedure is known to be less reliable, the recommended method is to use the GRUB shell.
Use the
grub-install
command followed by the location to install the boot loader. For example to install GRUB to the MBR of the first drive:
# grub-install /dev/sda
GRUB will indicate whether it successfully installs. If it does not, you will have to use the GRUB shell method.
Tips and tricks
Framebuffer resolution
One can use the resolution given in the
menu.lst
, but you might want to use your LCD wide-screen at its full native resolution. Here is what you can do to achieve this:
On
Wikipedia
, there is a list of extended framebuffer resolutions (i.e. beyond the ones in the VBE standard).
If the desired resolution does not work with the codes obtained from the table, it usually is because the graphics card manufacturers are free to choose any number they wish, as this is not part of the VBE 3 standard. These codes may change from one card to the other (possibly even for the same manufacturer).
Instead of using that table, use one of the tools mentioned below to get the correct code:
GRUB recognized value
This is an easy way to find the resolution code using only GRUB itself.
On the kernel line, specify that the kernel should ask you which mode to use.
kernel /vmlinuz-linux root=/dev/sda1 ro
vga=ask
Now reboot. GRUB will now present a list of suitable codes to use and the option to scan for even more.
You can pick the code you would like to use (do not forget it, it is needed for the next step) and boot using it.
Now replace
ask
in the kernel line with the correct one you have picked.
e.g. the kernel line for
[369] 1680x1050x32
would be:
kernel /vmlinuz-linux root=/dev/sda1 ro
vga=0x369
hwinfo
Install
the
hwinfo
package.
Run
hwinfo --framebuffer
as root.
Pick up the code corresponding to the desired resolution.
Use the 6 digit code with 0x prefix in
vga=
kernel option in
menu.lst
. Or convert it to decimal to avoid the use of 0x prefix.
Example output of
hwinfo
:
Mode 0x0364: 1440x900 (+1440), 8 bits
Mode 0x0365: 1440x900 (+5760), 24 bits
And the kernel line:
kernel /vmlinuz-linux root=/dev/sda1 ro
vga=0x0365
Naming partitions
By Label
If you alter (or plan to alter) partition sizes from time to time, you might want to consider defining your drive/partitions by a label. You can label ext2, ext3, ext4 partitions by:
e2label
/dev/drive|partition
label
The label name can be up to 16 characters long but cannot have spaces for GRUB to understand it. Then define it in your
menu.lst
:
kernel /boot/vmlinuz-linux root=/dev/disk/by-label/Arch_Linux ro
By UUID
The
UUID
(Universally Unique IDentifier) of a partition may be discovered with
blkid
or
ls -l /dev/disk/by-uuid
. It is defined in
menu.lst
with either:
kernel /boot/vmlinuz-linux root=/dev/disk/by-uuid/
uuid_number
or:
kernel /boot/vmlinuz-linux root=UUID=
uuid_number
Boot as root (single-user mode)
At the boot loader, select an entry and edit it (
e
key). Append the following parameters to the kernel options:
[...] single init=/bin/bash
This will start in single-user mode (init 1), i.e. you will end up to a root prompt without being asked for password.
This may be useful for recovery features, like resetting the root password.
However, this is a huge security flaw if you have not set any
#Password protection
for grub.
Password protection
You can enable password protection in the GRUB configuration file for operating systems you wish to have protected. Boot loader password protection may be desired if your BIOS lacks such functionality and you need the extra security.
First, choose a password you can remember and then encrypt it:
# grub-md5-crypt
Password:
 Retype password:
 $1$ZOGor$GABXUQ/hnzns/d5JYqqjw
Then add your password to the beginning of the GRUB configuration file at
/boot/grub/menu.lst
(the password must be at the beginning of the configuration file for GRUB to be able to recognize it):
# general configuration
timeout   5
default   0
color light-blue/black light-cyan/blue

password --md5 $1$ZOGor$GABXUQ/hnzns/d5JYqqjw
Note
Remember that Grub uses the standard QWERTY layout for input.
Then for each operating system you wish to protect, add the
lock
command:
# (0) Arch Linux
title  Arch Linux
lock
root   (hd0,1)
kernel /boot/vmlinuz-linux root=/dev/disk/by-label/Arch_Linux ro
initrd /boot/initramfs-linux.img
Warning
If you disable booting from other boot devices (like a CD drive) in the BIOS's settings and then password protect all your operating system entries, it could be difficult to re-enable booting back into the operating systems if the password is forgotten.
It is always possible to reset your BIOS settings by setting the appropriate jumper on the motherboard (see your motherboard's manual, as it is specific to every model). So in case other have access to the hardware, there is basically no way to prevent boot breakthroughs.
Restart with named boot choice
If you realize that you often need to switch to some other non-default OS (e.g. Windows) having to reboot and wait for the GRUB menu to appear is tedious. GRUB offers a way to record your OS choice when restarting instead of waiting for the menu, by designating a temporary new default which will be reset as soon as it has been used.
Supposing a simple
menu.lst
setup like this:
/boot/grub/menu.lst
# general configuration:
timeout 10
default 0
color light-blue/black light-cyan/blue

# (0) Arch
title  Arch Linux
root (hd0,1)
kernel /boot/vmlinuz-linux root=/dev/disk/by-label/ARCH ro
initrd /boot/initramfs-linux.img

# (1) Windows
title Windows XP
rootnoverify (hd0,0)
makeactive
chainloader +1
Arch is the default (0). We want to restart in to Windows. Change
default 0
to
default saved
-- this will record the current default in a
default
file in the GRUB directory whenever the
savedefault
command is used. Now add the line
savedefault 0
to the bottom of the Windows entry. Whenever Windows is booted, it will reset the default to Arch, thus making changing the default to Windows temporary.
Now all that is needed is a way to easily change the default manually. This can be accomplished using the command
grub-set-default
. So, to reboot into Windows, enter the following commands:
# grub-set-default 1
Then reboot.
For ease of use, you might wish to
setup sudo
and add
/sbin/grub-set-default
amongst the commands the user is allowed to issue without supplying a password.
LILO and GRUB interaction
If the
LILO
package is installed on your system,
uninstall
it. As some tasks (e.g. kernel compilation using
make all
) will make a LILO call, and LILO will then be installed over GRUB. LILO may have been included in your base system, depending on your installer media version and whether you selected/deselected it during the package selection stage.
Note
Removing
lilo
AUR
will not remove LILO from the MBR if it has been installed there; it will merely remove the
lilo
AUR
package. LILO installed to the MBR will be overwritten when GRUB (or another boot loader) is installed over it.
GRUB boot disk
First, format a floppy disk:
# fdformat /dev/fd0
# mke2fs /dev/fd0
Now mount the disk:
# mount -t ext2 /dev/fd0 /mnt/fl
Install GRUB to the disk:
# grub-install --root-directory=/mnt/fl '(fd0)'
Copy your
menu.lst
file to the disk:
# cp /boot/grub/menu.lst /mnt/fl/boot/grub/menu.lst
Now unmount your floppy:
# umount /mnt/fl
Now you should be able to restart your computer with the disk in the drive and it should boot to GRUB. Make sure that your floppy disk is set to have higher priority than your hard drive when booting in your BIOS first, of course.
See also:
Super GRUB Disk
.
Hide GRUB menu
The
hiddenmenu
option can be used in order to hide the menu by default. That way no menu is displayed and the default option is going to be automatically selected after the timeout passes.
Still, you are able to press
Esc
and the menu shows up. To use it, just add to your
/boot/grub/menu.lst
:
hiddenmenu
Troubleshooting
GRUB Error 17
Note
the solution below works also for GRUB Error 15
The first check to do is to unplug any external drive. Seems obvious, but sometimes we get tired ;)
If your partition table gets messed up, an unpleasant "GRUB error 17" message might be the only thing that greets you on your next reboot. There are a number of reasons why the partition table could get messed up. Commonly, users who manipulate their partitions with
GParted
-- particularly logical drives -- can cause the order of the partitions to change. For example, you delete
/dev/sda6
and resize
/dev/sda7
, then finally re-create what used to be
/dev/sda6
only now it appears at the bottom of the list,
/dev/sda9
for example. Although the physical order of the partitions/logical drives has not changed, the order in which they are recognized has changed.
Fixing the partition table is easy. Boot from your Arch CD/DVD/USB, login as root and fix the partition table:
# fdisk /dev/sda
Once in disk, enter e[x]tra/expert mode, [f]ix the partition order, then [w]rite the table and exit.
You can verify that the partition table was indeed fixed by issuing an
fdisk -l
. Now you just need to fix GRUB. See
#Boot loader installation
.
Basically you need to tell GRUB the correct location of your
/boot
then re-write GRUB to the
MBR
on the disk.
For example:
# grub
grub> root (hd0,6)
grub> setup (hd0)
grub> quit
See
[1]
for a more in-depth summary of this section.
/boot/grub/stage1 not read correctly
If you see this error message while trying to set up GRUB, and you are not using a fresh partition table, it is worth checking it.
# fdisk -l /dev/sda
This will show you the partition table for
/dev/sda
. So check here, whether the "Id" values of your partitions are correct. 
The "System" column will show you the description of the "Id" values.
If your boot partition is marked as being "HPFS/NTFS", for example, then you have to change it to "Linux". To do this, go to fdisk,
# fdisk /dev/sda
change a partition's system id with
t
, select your partition number and type in the new system id (Linux = 83). 
You can also list all available system ids by typing
L
instead of a system id.
If you have changed a partitions system id, you should [v]erify your partition table and then [w]rite it.
Now try to set up GRUB again.
See also the
forum post
reporting this problem.
Accidental install to a Windows partition
If you accidentally install GRUB to a Windows partition, GRUB will write some information to the boot sector of the partition, erasing the reference to the Windows boot loader. (This is true for NTLDR the boot loader for Windows XP and earlier, unsure about later versions).
To fix this you will need to use the Windows Recovery Console for your Windows release. Because many computer manufacturers do not include this with their product (many choose to use a recovery partition) Microsoft has made them available for download. If you use XP, look at
this page
to be able to turn the floppy disks to a Recovery CD. Boot the Recovery CD (or enable Windows Recovery mode) and run
fixboot
to repair the partition boot sector. After this, you will have to install GRUB again---this time, to the MBR, not to the Windows partition---to boot Linux.
Edit GRUB entries in the boot menu
Once you have selected an entry in the boot menu, you can edit it by pressing key
e
. Use tab-completion if you need to discover devices then
Esc
to exit. Then you can try to boot by pressing
b
.
Note
These settings
will not be saved
.
device.map error
If an error is raised mentioning
/boot/grub/device.map
during installation or boot, run:
# grub-install --recheck /dev/sda
to force GRUB to recheck the device map, even if it already exists. This may be necessary after resizing partitions or adding/removing drives.
KDE reboot pull-down menu fails
If you have opened a sub-menu with the list of all operating systems configured in GRUB, selected one, and upon restart, you still booted your default OS, then you might want to check if you have the line:
default saved
in
/boot/grub/menu.lst
.
GRUB fails to find or install to any virtio
/dev/vd*
or other non-BIOS devices
I had trouble installing GRUB while installing Arch Linux in an virtual KVM machine using a virtio device for hard drive. To install GRUB, I figured out the following:
Enter a virtual console by typing
Ctrl+Alt+F2
or any other F-key for a free virtual console.
This assumes that your root file system is mounted in the folder
/mnt
and the boot file system is either mounted or stored in the folder
/mnt/boot
.
1.
Assure that all needed GRUB files is present in your boot directory (assuming it is mounted in
/mnt/boot
folder), by issuing the command:
# ls /mnt/boot/grub
2.
If the
/mnt/boot/grub
folder already contains all the needed files, jump to step 3. Otherwise, do the following commands (replacing
/mnt
,
your_kernel
and
your_initramfs
with the real paths and file names). You should also have the
menu.lst
file written to this folder:
# mkdir -p /mnt/boot/grub                # if the folder is not yet present
# cp -r /boot/grub/stage1 /boot/grub/stage2 /mnt/boot/grub
# cp -r
your_kernel
your_initramfs
/mnt/boot
3.
Start the GRUB shell with the following command:
# grub --device-map=/dev/null
4.
Enter the following commands. Replace
/dev/vda
, and
(hd0,0)
with the correct device and partition corresponding to your setup.
device (hd0) /dev/vda
root (hd0,0)
setup (hd0)
quit
5.
If GRUB reports no error messages, then you probably are done. You also need to add appropriate modules to the ramdisk. For more information, please refer to
QEMU#Preparing an Arch Linux guest
.
See also
GNU GRUB
GRUB Grotto
Boot debugging
- Debugging with GRUB, set module values
Boot with GRUB
legacy