grub issues during FAI install

[Toni Mueller]

Hi,

On Wed, 08.07.2009 at 10:50:07 +0200, Steffen Grunewald <steffen.grunewald at aei.mpg.de> wrote:
> I'm using the /boot/grub/menu.lst/GRUB example that comes with FAI, and
> the corresponding postinst. (Lenny, AMD64)
> After fcopy'ing /boot/grub/menu.lst, I usually see the following messages
> produced by the postinst script:
> 
> grub-probe: error: Cannot open `/boot/grub/device.map'
> /usr/sbin/grub-install: line 374: [: =: unary operator expected

I think this error was corrected in 3.2.20, or at least, I don't see it
there anymore.

> (hd0)<->/dev/sda
> (hd1)<->/dev/sdb
> Searching for GRUB installation directory ... found: /boot/grub
> Searching for default file ... found: /boot/grub/default
> Testing for an existing GRUB menu.lst file ... found: /boot/grub/menu.lst
> Searching for splash image ... none found, skipping ...
> Found kernel: /boot/vmlinuz-2.6.26-2-amd64
> Updating /boot/grub/menu.lst ... done
> 
> Grub installed on /dev/sda on (hd0,0)

I don't know where you get this from (congrats if it works for you).

> Since the "line 374" error appears to be related to a missing device.map, 
> and everything seems to work fine, I'm not worried too much about it.

My result is that after a reboot, I get "No OS", and the machine hangs.

> - and closer examination shows that in disk_var.sh, there's a line
> BOOT_DEVICE="/dev/sda /dev/sdb"
> when it should read
> BOOT_DEVICE="/dev/sda"
> only.

I have exactly this behaviour on my machine. Recently, a discussion
popped up somewhere as to what FAI should do in that case, because you
don't want grub on one disk only, but on both. Otherwise, you're toast
if that one disk goes bad, and you spent the effort of running a RAID
in vain.

I'm not sure what to do there, either, but if I knew what to do, it
should be simple enough to split the BOOT_DEVICE variable into an array
and run grub-install on each of them. The remaining question is what to
tell grub about the disk configuration, imho. It would be great if
someone could lend a hand here, or share some relevant pointers.

> For whatever reason this has happened: it shouldn't. There could be
> several reasons to have multiple bootable devices (e.g. different
> OSes), and they should be selectable in the BIOS. 

I really have to disagree here. Fiddling with the BIOS soundly defeats
any reason to use automatic installation methods in the first place,
and may be infeasible for a good portion of use cases, too. As I said
above, the first reason to be able to boot from several disks is to be
able to boot from the second (third, ...) disk in a RAID pack.

As long as we stay with grub (I have no other suggestion to make),
booting different operating systems should be attainable by modifying
menu.lst appropriately, and should imho have nothing to do with the
BIOS settings of the machine(s) in question.


Kind regards,
--Toni++