update-grub: mess in menuentry in grub.cfg

[midenok]

After `update-grub` the following output is generated:

```
 menuentry 'Ubuntu, with Linux 2.6.35-22-generic (on /dev/mapper/vvg0-root)'\'' --class gnu-linux --class gnu --class os $menuentry_id_option '\''osprober-gnulinux-/boot/vmlinuz-2.6.35-22-generic--0ed5e93c-99f4-48ec-8b13-1b34b52852f5 (on /dev/mapper/vvg0-root)' --class gnu-linux --class gnu --class os $menuentry_id_option 'osprober-gnulinux-/boot/vmlinuz-2.6.35-22-generic--0ed5e93c-99f4-48ec-8b13-1b34b52852f5' {
  insmod lvm
  insmod lvm
  insmod ext2
  set root='lvmid/ODtXBF-9DiG-LZ2p-dI92-qJZc-9G9g-XBmgcH/grLDh5-eAcC-DEZU-gEcc-QoBR-OUlI-ik2t1l'
  if [ x$feature_platform_search_hint = xy ]; then
    search --no-floppy --fs-uuid --set=root --hint='lvmid/ODtXBF-9DiG-LZ2p-dI92-qJZc-9G9g-XBmgcH/grLDh5-eAcC-DEZU-gEcc-QoBR-OUlI-ik2t1l' 0ed5e93c-99f4-48ec-8b13-1b34b52852f5
  else
    search --no-floppy --fs-uuid --set=root 0ed5e93c-99f4-48ec-8b13-1b34b52852f5
  fi
  linux /boot/vmlinuz-2.6.35-22-generic root=UUID=e673fbdf-b413-4ac9-b05c-574aa15535e4 ro vga=normal nomodeset crashkernel=384M-2G:64M,2G-:128M nosplash
  initrd /boot/initrd.img-2.6.35-22-generic
 }
```

Note, that 'insmod lvm' is done two times. $root variable is ignored! root option is passed like 'root=UUID=e673fbdf-b413-4ac9-b05c-574aa15535e4', all root magic from above is ignored which leads to wrong mounted root filesystem.

The proper menuentry should look like:

```
 menuentry 'Ubuntu, with Linux 2.6.35-22-generic (on /dev/mapper/vvg0-root)'\'' --class gnu-linux --class gnu --class os $menuentry_id_option '\''osprober-gnulinux-/boot/vmlinuz-2.6.35-22-generic--0ed5e93c-99f4-48ec-8b13-1b34b52852f5 (on /dev/mapper/vvg0-root)' --class gnu-linux --class gnu --class os $menuentry_id_option 'osprober-gnulinux-/boot/vmlinuz-2.6.35-22-generic--0ed5e93c-99f4-48ec-8b13-1b34b52852f5' {
  insmod lvm
  insmod ext2
  set root='lvmid/ODtXBF-9DiG-LZ2p-dI92-qJZc-9G9g-XBmgcH/grLDh5-eAcC-DEZU-gEcc-QoBR-OUlI-ik2t1l'
  if [ x$feature_platform_search_hint = xy ]; then
    search --no-floppy --fs-uuid --set=root --hint=$root 0ed5e93c-99f4-48ec-8b13-1b34b52852f5
  else
    search --no-floppy --fs-uuid --set=root $root
  fi
  linux /boot/vmlinuz-2.6.35-22-generic root=$root ro vga=normal nomodeset crashkernel=384M-2G:64M,2G-:128M nosplash
  initrd /boot/initrd.img-2.6.35-22-generic
 }
```

I would want to ask people, who did such artful programming: do you look at the output of your scripts at all?

Version: 2.02~beta2-9ubuntu1

[midenok (midenok)]

Don't quite understand to do first `set root='lvmid/ODtXBF-9DiG-LZ2p-dI92-qJZc-9G9g-XBmgcH/grLDh5-eAcC-DEZU-gEcc-QoBR-OUlI-ik2t1l'` and then check $feature_platform_search_hint. Where is the logic?

[midenok (midenok)]

The output came from 30_os-prober. Please, forward bug to upstream.

[midenok (midenok)]

Upstream: https://savannah.gnu.org/bugs/index.php?43390

[Phillip Susi (psusi)]

The root variable is used by grub to find files. Its form is that of a grub device name, which the kernel does not understand, therefore it can not be passed to the kernel as its root argument.

[midenok (midenok)]

1. Variables get expanded before executing line. No one tries to "pass" variable to kernel.
2. 'Mess' is in wrong root= parameter (UUID=e673fbdf-b413-4ac9-b05c-574aa15535e4), should be lvmid/ODtXBF-9DiG-LZ2p-dI92-qJZc-9G9g-XBmgcH/grLDh5-eAcC-DEZU-gEcc-QoBR-OUlI-ik2t1l

[midenok (midenok)]

Ok, if format of $root variable is incompatible with root= parameter (which is at least weird), then root= parameter should be set to correct boot device (/dev/mapper/vvg0-root). It just boots wrong device (/dev/sda1).

[Phillip Susi (psusi)]

Normally if the root is on an lvm volume, /etc/grub.d/10_linux passes the lvm name instead of the UUID to the kernel. Did you originally have this sytem installed on a plain volume and then migrate it to a logical volume? If so, you will need to edit the the grub.cfg in that volume to change it to point to the lvm name and then re-run update-grub to pick up the change into your master grub.cfg.

[Mathieu Trudel-Lapierre (cyphermox)]

What do 'blkid' and 'blkid -U e673fbdf-b413-4ac9-b05c-574aa15535e4' report? Are all the values matching?

We seem to not be using LVM UUIDs and instead taking the device mapper paths now; perhaps this was fixed in a newer release?

[Launchpad Janitor (janitor)]

[Expired for grub2 (Ubuntu) because there has been no activity for 60 days.]