update-grub(8)update-grub(8)NAMEupdate-grub - program to generate GRUB's menu.lst file
SYNOPSISupdate-grubDESCRIPTIONupdate-grub is a program used to generate the menu.lst file used by the
grub bootloader. It works by looking in /boot for all files which
start with "vmlinuz-". They will be treated as kernels, and grub menu
entries will be created for each. It will also create the initial
menu.lst if none exists, after prompting the user. It will also add
initrd lines for ramdisk images found with the same version as kernels
found. e.g. /boot/vmlinuz-2.4.5 and /boot/initrd-2.4.5 will cause a
line of "initrd=/boot/initrd-2.4.5 or similar to be added for the ker‐
nel entry in the menu.lst.
After update-grub has been run for the first time, the user is required
to edit the generated menu.lst. The user must set the two options
update-grub uses. Then re-run the update-grub script to update the
menu.lst file using the default's that have been set.
These are the options passed to the linux kernel:
# kopt=root=/dev/hda1 ro
Everything after "kopt=" is passed to the kernel as parameters. See
bootparam(7) for more information.
This is the grub device from which grub loads the kernel:
# groot=(hd0,1)
(hd0,1) is a partition in grub notation. See grub(8) for more informa‐
tion.
This option controls if grub should create the alternative boot options
in the menu entries
# alternative=true
# alternative=false
This option controls if grub should lock the alternative boot options
see grub(8) for more information.
# lockalternative=true
# lockalternative=false
This option controls if grub should lock the old kernels.
# lockold=true
# lockold=false
This options controls what is used for the alternative boot options,
multiple altoptions lines are allowed.
# altoptions=(some description) some kernel command line options
# altoptions=(recovery option) single
The description is placed in '()' and the kernel command line options
follow that.
# updatedefault=true
# updatedefault=false
This option controls if grub should update the default entry to keep
booting the same kernel even if a new one is installed.
The update-grub script can be ran automagically from the /etc/ker‐
nel-img.conf file by adding the following lines:
postinst_hook = update-grub
postrm_hook = update-grub
do_bootloader = no
For further information related to /etc/kernel-img.conf, see the man‐
page kernel-img.conf(5).
SEE ALSOgrub(8), grub-install(8), kernel-img.conf(5) (contained in the kernel-
package package), bootparam(7).
The full documentation for grub is maintained as a Texinfo manual in
the grub-legacy-doc package. If the info and grub programs are prop‐
erly installed at your site, the command
info grub
should give you access to the complete manual.
AUTHOR
This manual page was written by Jason Thomas <jason@debian.org>, for
the Debian GNU/Linux system (but may be used by others).
Jason Thomas June 18, 2001 update-grub(8)
