[BZR BRANCH] [RFC] mdraid 1.x metadata support

[Felix Zielcke]

I made now a branch for supporting the mdraid 1.x metadata

 bzr+ssh://bzr.savannah.gnu.org/grub/people/fzielcke/raid
 http://bzr.savannah.gnu.org/r/grub/people/fzielcke/raid

The problem with 1.x is that there's no more a prefered minor stored in
the superblock but only a name.
I currently use it now directly as a GRUB device, without checking for
duplicates.
The problem is only that `grub-probe -t drive' still uses the /dev/
filename for the output.
So we need again a way to map a Linux device to a GRUB device.
For now either use mdadm -Q --detail /dev/md0 to see what it assigned as
`Name:' or grub-emu.

The second problem is that the name probable doestn't need to be unique.
How should I solve that problem?
Just using name0 if name is taken and after name9 then name10?
Someone on #debian-devel suggested to just use UUIDs as GRUB devices but
I don't like that and I don't think many users do.
The Debian mdadm maintainer also said we should only rely on UUIDs and
not on the Linux device names for mdraid.

With LVM we also have the problem for duplicates, but this is very very
rarely.

-- 
Felix Zielcke
Proud Debian Maintainer and GNU GRUB developer