[Bug 591454] Re: grub-probe: cannot find a device for /boot/grub

[Azyl]

Hi All,

In my case the issue was caused due to the fact that i have used a btrfs
filesystem for my root partition and as Nils mentioned if you just mount
the /dev/sdx to mnt and then mount --bind all the nedeed parts, chroot
and try to update grub or grub-install the comands will both fail as you
need to mount the default subvolume bellow i described how i managed to
do that:

I recomend that you

In case of btrfs mount the drive to a temp dir then find the ID of the
btrfs subvolumes or snapshots with

 btrfs subvolume list / where / is the path to a temp directory where
you have mounted the /dev/sdx btrfs filesystem


and in order to mount the desired subvolumne issue mount /dev/sda6 -o subvolid=ID /mnt

where ID is the ID returned by btrfs subvolume list
/path_to_temp_mount_folder

After that you can continue asn normal with the grub rescue :P:

sudo mount --bind /dev /mnt/dev && sudo mount --bind /proc /mnt/proc &&
sudo mount --bind /sys /mnt/sys && sudo mount --bind /dev/pts
/mnt/dev/pts && sudo cp /etc/resolv.conf /mnt/etc/resolv.conf && sudo
chroot /mnt

update-grub or grub-install /dev/sdax


Hope this help other as the previos comment gaved me a nice hint to solve my issue.

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https://bugs.launchpad.net/bugs/591454

Title:
  grub-probe: cannot find a device for /boot/grub

Status in Software Updater:
  New
Status in grub2 package in Ubuntu:
  Confirmed

Bug description:
  Binary package hint: grub2

  dpkg: dependency problems prevent configuration of ubuntu-standard:
   ubuntu-standard depends on memtest86+; however:
    Package memtest86+ is not configured yet.
  dpkg: error processing ubuntu-standard (--configure):
   dependency problems - leaving unconfigured
  Setting up grub-pc (1.98-1ubuntu6) ...
  /usr/sbin/grub-probe: error: cannot find a device for /boot/grub (is /dev mounted?).
  No path or device is specified.
  Try `/usr/sbin/grub-probe --help' for more information.
  Auto-detection of a filesystem module failed.
  Please specify the module with the option `--modules' explicitly.

  ProblemType: Package
  DistroRelease: Ubuntu 10.04
  Package: grub-pc 1.98-1ubuntu6
  ProcVersionSignature: Ubuntu 2.6.31-22.60-generic
  Uname: Linux 2.6.31-22-generic x86_64
  Architecture: amd64
  Date: Tue Jun  8 22:41:58 2010
  ErrorMessage:
   ErrorMessage: subprocess installed post-installation script returned error exit status 1
  SourcePackage: grub2
  Title: package grub-pc 1.98-1ubuntu6 failed to install/upgrade:

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