Grub install fails to Raid1

[Richard Laysell]

Binary package hint: debian-installer

Installing Lucid (10.04) Alpha 3 to a system fails at the Grub install part with the following dialog box

        [!!] Configuring grub-pc
Unable to install GRUB in /dev/sda
Executing 'grub-install /dev/sda' failed.
         This is a fatal error
    <Go Back> <Continue>

If I go back and try again I get the same error. If I continue, and install LILO as the boot loader it works (but I would prefer to use GRUB).

The system has two disks with three partitions on each
/dev/sda
/dev/sda1 - 50Gig NTFS - Not used for this install
/dev/sda2 - 256Meg - Raid (part of md0) to be used as /boot
/dev/sda3 - 270Gig - Raid (part of md1) used for LVM (which then has /, swap, /var, /home)

/dev/sdb - same partitions as /dev/sda

If I redo the install, but use /dev/sda2 as a ext4 device with /boot on it (i.e. no raid) it works fine - grub installs and I can boot after the install completes.

[Richard Laysell (ubuntu-bugs-ailanthus)]

The underlying problem is that the /boot/grub/device.map file was missing

Managed to get this working by doing the following.

Boot from the CDROM and run 'Rescue a Broken System'
Run a shell on the root partition
Mount /boot and /var
Run the command '/usr/sbin/grub-mkdevicemap -n'
Run the command '/usr/sbin/grub-install /dev/sda'
Run the command '/usr/sbin/grub-install /dev/sdb' (for completeness - this is a mirrored system)
Run the command '/usr/sbin/update-grub2'

Reboot - and it all works

[Colin Watson (cjwatson)]

device.map is deliberately missing in Lucid - we're trying to phase it
out because it causes lots of other problems. Evidently we have some
more work to do in this case.

[Mark Foster (fostermarkd)]

I ran into this also. Attaching screenshots and debug logs in case it helps.

[Colin Watson (cjwatson)]

I fixed this as bug 527401, and did a successful end-to-end test with the final piece of the puzzle today. It was broken in 10.04 beta-1, but it'll be fixed in beta-2. You can also try tomorrow's daily build, although they're broken at the moment for a different reason; if I can manage to get the timing right to have that fixed for tomorrow's builds, I'll do my best.

[bastafidli (ubuntu-bastafidli)]

FYI, the above steps didnt work for me on my SW RAID 1 residing on /dev/sdc and /dev/sdd. I will retry once beta 2 is out.