Bug#557473: 30_os-prober generates invalid boot entries

[Felix Zielcke]

Am Sonntag, den 22.11.2009, 12:14 +0100 schrieb Harald Dunkel:
> Package: grub-common
> Version: 1.97+20091115-1
> 
> I've got a root partition using raid0 (2 disks), and a regular boot
> partition, usually mounted on /boot:
> 
> % df
> Filesystem           1K-blocks      Used Available Use% Mounted on
> /dev/md0p1            33553404   6486848  27066556  20% /
> tmpfs                  2030704         0   2030704   0% /lib/init/rw
> udev                     10240       344      9896   4% /dev
> tmpfs                  2030704         0   2030704   0% /dev/shm
> /dev/sdb1             33558712    353776  33204936   2% /boot
> 
> Problem: /etc/grub.d/30_os-prober adds entries for /dev/md0p1 to
> grub.cfg, even though /boot is on /dev/sdb1 

It uses /dev/md0p3 not p1

> (not to mention that
> grub2 does not support raid0). See attachment.

mdraid 0 is supported fine.
The only thing from the Linux Software RAID that isn't yet supported is
the metadata 1.x format. Only the older 0.90 superblocks are supported.
But I made initial support for 1.x in a Bazaar branch. See the last
message in #554500

> If I select an entry generated via os-prober at boot time, then I get
> a message that I have to load a kernel first.

### BEGIN /etc/grub.d/30_os-prober ###
menuentry "Debian GNU/Linux, with Linux 2.6.32-rc8 (on /dev/md0p3)" {
        search --no-floppy --fs-uuid --set f3f11a99-cd48-49ae-9455-189ad251b209
        linux /boot/vmlinuz-2.6.32-rc8 root=UUID=e8d59336-6621-4061-96f7-fe294e58b3ce ro video=vesafb:ypan quiet

What is on /dev/md0p3 or the filesystem with this UUID
f3f11a99-cd48-49ae-9455-189ad251b209?
The root=UUID= for the linux kernel seems to be your /dev/md0p1 because
it's the same as in the 10_linux Linux entries.
os-prober/linux-boot-prober (not 30_os-prober, it's a seperate Debian
package) looks for all /etc/lilo.conf, (/boot)/grub/grub.cfg and
(/boot)/grub/menu.lst it can find.
And we just make in 30_os-prober from its output a proper GRUB 2
menuentry.

The main question here is, should os-prober add these entries or not.
If it should and the entries in the bootloader configuration for this
other Debian system is correct from it's point of view, then it's just
the bug with a seperate /boot partition.
That bug is already fixed upstream by me yesterday.

-- 
Felix Zielcke
Proud Debian Maintainer and GNU GRUB developer