[Bug 987354] Re: error: no such partition. grub-pc fails to detect mdraid partitions

[TJ]

This is caused when the existing GRUB configuration is incorrect and
GRUB only 'knows' about one disk in the MD RAID set.

In this instance there is a RAID-1 mirror array of two disks on the
first two IDE PATA controller ports (both as masters).

When the system boots BIOS does not know anything about software RAID
devices so it reads the grub bootloader files from one drive. If that
drive hasn't been updated by 'update-grub' then it will have older
binary files on it.

When the GRUB package changes enough that the Application Binary
Interface (ABI) changes it means that the older binaries cannot load
grub's support libraries since the entry points and function signatures
have changed.

A work-around to get the system booted is to enter the BIOS set-up and
change the order of the disks in the DM RAID array so the disk with the
updated master boot record is read first. This is easy to figure out if
it is a 2-disk mirror.

Once the system is started do:

dpkg-reconfigure grub-pc

and ensure all disks the system might boot from are selected.

** Changed in: grub2 (Ubuntu)
     Assignee: TJ (intuitivenipple) => (unassigned)

** Changed in: grub2 (Ubuntu)
       Status: In Progress => Confirmed

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https://bugs.launchpad.net/bugs/987354

Title:
  error: no such partition. grub-pc fails to detect mdraid partitions

Status in “grub2” package in Ubuntu:
  Confirmed
Status in “grub2” package in Debian:
  Unknown

Bug description:
  After upgrading Oneiric to Precise on a 32-bit server that has md-raid
  mirrored boot drives using:

  do-release-upgrade -d

  On reboot GRUB2 totally fails to find its 2nd stage files. It reports:

  error: no such partition

  This also happens when entering the rescue command-line and trying to
  do operations such as:

  grub> ls
  error: no such partition

  Initial inspection of the grub environment indicates the UUIDs and
  grub prefix are as they were prior to the update.

  It is not possible to do anything with GRUB2 that requires it to
  find/load second stage files - which puts most of its command-line
  tools out of reach.

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