Re: grub-pc jumps straight to rescue and prints error: no such disk / file not found

[Josip Rodin]

On Sat, Jan 02, 2010 at 02:29:36PM +0100, Josip Rodin wrote:
> I've got two disks and a software RAID setup on the partition that holds
> the /boot directory. I have several Linux software RAID partitions, based
> on this scheme:
> 
> sda2+sdb2     -> Linux amd64 /
> sda3+sdb3     -> Linux i386 /
> sda4+sdb4     -> Linux swap
> sda5+sdb5     -> Linux /home
> 
> The first two become md0, differentiated by old GRUB menu entries -
> Linux parameters raid=noautodetect and md0=first,second ... settings.
> The second two become md1 and md2, respectively, and the fourth array
> is simply left unassembled on the non-applicable architecture.

I forgot about the MBR format and the extended partition so the number
offsets for swap and home are 5 and 6, but either way, the numbers for the
two Linux root partitions are correct.

I later noticed that 'ls /' while changing the root variable gives me a
simple way to detect which is which from the rescue shell. So I then set
root=(md3), and set prefix to use one as well, and am able to get to my
menu by running insmod normal, insmod configfile, configfile
/boot/grub/grub.cfg. Yay!

But then I got briefly derailed again - my autogenerated menu entry for the
amd64 root partition seemed to have the wrong UUID in the 'search' command.
That sounds like a userland issue, because:

% sudo grub-probe -d /dev/sda1 -t fs_uuid
1460509560508002
% sudo grub-probe -d /dev/sda2 -t fs_uuid
18515dea-973e-473b-bddf-74d1cb58e15a
% sudo grub-probe -d /dev/sda3 -t fs_uuid
7e6cdce7-8136-41f0-8a66-997b89ea00fe

And yet after running the update-grub command on the amd64 machine
I still get:

% grep search /boot/grub/grub.cfg | sort -u
        search --no-floppy --fs-uuid --set 1460509560508002
        search --no-floppy --fs-uuid --set 7e6cdce7-8136-41f0-8a66-997b89ea00fe

It's supposed to detect the amd64 partition (sda2) at least once :)
but it seems to be fixating on the i386 one (sda3).

-- 
     2. That which causes joy or happiness.