Meanwhile we have 2025 and the bug is STILL THERE!
I have a host with LVM and 2 Linux partitions:
root at fextest01:/etc/default# lsblk -o NAME,SIZE,FSTYPE,LABEL,Mountpoint
NAME SIZE FSTYPE LABEL MOUNT
sr0 1024M
vda 50G
|-vda1 1M
|-vda2 2G ext4 /boot
`-vda3 48G LVM2_member
|-ubuntu--vg-ubuntu--lv 24G ext4 /
`-ubuntu--vg-U24 24G btrfs U24
root at fextest01:/etc/default# update-grub
Sourcing file `/etc/default/grub'
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-6.8.0-57-generic
Found initrd image: /boot/initrd.img-6.8.0-57-generic
Found linux image: /boot/vmlinuz-6.8.0-56-generic
Found initrd image: /boot/initrd.img-6.8.0-56-generic
Warning: os-prober will be executed to detect other bootable partitions.
Its output will be used to detect bootable binaries on them and create new boot entries.
Found Ubuntu 24.04.2 LTS (24.04) on /dev/mapper/ubuntu--vg-U24
Adding boot menu entry for UEFI Firmware Settings ...
done
Looks ok so far, but when I reboot and select the second entry ubuntu--vg-U24 in grub menu, then grub uses the wrong root partition /dev/mapper/ubuntu--vg-ubuntu--lv
I see in /boot/grub/grub.cfg :
### BEGIN /etc/grub.d/30_os-prober ###
menuentry 'Ubuntu 24.04.2 LTS (24.04) (on /dev/mapper/ubuntu--vg-U24)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'osprober-gnulinux-simple-0021fed9-be1d-486e-8b3e-619955a39dea' {
insmod part_gpt
insmod ext2
search --no-floppy --fs-uuid --set=root 25c4ca64-579d-4782-a55e-f66eacb131af
linux /vmlinuz-6.8.0-57-generic root=/dev/mapper/ubuntu--vg-ubuntu--lv ro console=ttyS0,115200
initrd /initrd.img-6.8.0-57-generic
There should be root=/dev/mapper/ubuntu--vg-U24 and not root=/dev/mapper/ubuntu--vg-ubuntu--lv !
--
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to grub2 in Ubuntu.
https://bugs.launchpad.net/bugs/508901
Title:
update-grub sets wrong root argument
Status in grub2 package in Ubuntu:
Confirmed
Bug description:
Binary package hint: grub2
I've made a backup of my system with dd and then changed the UUID and
label of the drive. I would like to be able to boot from either the
main system or the backup, ideally regardless of whether the backup is
in a USB enclosure or mounted internally.
When I run update-grub, even though it correctly finds the backup and
uses its UUID as a parameter for the search command, it still sets the
root= argument of the linux command to the main system. This makes
the backup unusable.
So in my setup, the original drive is
7f0e857e-6118-4696-bdc6-7c51b31e1002, and the backup is
9de2fc84-1128-41eb-9c1b-a444d070d415. Each one has its fstab set up
to mount itself as root. The generated boot options look like this:
### BEGIN /etc/grub.d/10_linux ###
menuentry "Ubuntu, Linux 2.6.31-17-generic" {
recordfail=1
if [ -n ${have_grubenv} ]; then save_env recordfail; fi
set quiet=1
insmod ext2
set root=(hd0,1)
search --no-floppy --fs-uuid --set 7f0e857e-6118-4696-bdc6-7c51b31e1002
linux /boot/vmlinuz-2.6.31-17-generic root=/dev/sda1 ro quiet splash
initrd /boot/initrd.img-2.6.31-17-generic
}
...
### BEGIN /etc/grub.d/30_os-prober ###
menuentry "Ubuntu, Linux 2.6.31-17-generic (on /dev/sdb1)" {
insmod ext2
set root=(hd1,1)
search --no-floppy --fs-uuid --set 9de2fc84-1128-41eb-9c1b-a444d070d415
linux /boot/vmlinuz-2.6.31-17-generic root=UUID=7f0e857e-6118-4696-bdc6-7c51b31e1002 ro quiet splash
initrd /boot/initrd.img-2.6.31-17-generic
}
I tried uncommenting the GRUB_DISABLE_LINUX_UUID=true" line in
/etc/default/grub, but it only affects the output of 10_linux, not
30_os-prober.
ProblemType: Bug
Architecture: i386
Date: Sun Jan 17 21:07:18 2010
DistroRelease: Ubuntu 9.10
Package: grub2 1.97~beta4-1ubuntu4.1
ProcEnviron:
LANGUAGE=en_GB.UTF-8
PATH=(custom, user)
LANG=en_GB.UTF-8
SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-17.54-generic
SourcePackage: grub2
Uname: Linux 2.6.31-17-generic i686
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/508901/+subscriptions