[TriLUG] Grub question

Rick DeNatale rick.denatale at gmail.com
Fri Feb 17 10:16:51 EST 2006


Some of you might have been following the conversation I've been
having with Brian M. about migrating my system to use Raid1.

I've gotten myself a little confused about how grub is mapping my drives.

The system has two SCSI drives and two IDE drives.  Right now the only
bootable drive is /dev/sda

The entries in my /boot/grub/menu.list look like this:
title           Ubuntu, kernel 2.6.12-10-686-smp
root            (hd0,0)
kernel          /vmlinuz-2.6.12-10-686-smp
root=/dev/mapper/Ubuntu-root ro quiet splash
initrd          /initrd.img-2.6.12-10-686-smp
savedefault
boot

Which makes sense, but  there's also a /boot/grub/device.map that looks like
(hd0)   /dev/hdc
(hd1)   /dev/hdd
(hd2)   /dev/sda
(hd3)   /dev/sdb

Since the system boots, and /dev/sda has the only bootable partition
then grub must be mapping (hd0,0) to /dev/sda right?

Nivek may remember that when he helped me migrate this system to
Ubuntu at the last install fest, we had a problem in that the Ubuntu
installer set things up to boot from /dev/hdc and we had to muck with
the grub configuration.  I had the same problem when I had to rebuild
the system.  My fix was to edit /boot/grub/menu.lst to change the
(hd2,..) entries which the Ubuntu installer had put there to
(hd0,...).

Any insight as to what's going on here.  It looks like grub isn't
looking at device.map at boot time, although Ubuntu seemed to think
that it would.  I don't see how you actually tell grub to boot using
device.map since it's a parameter to the grub command.

--
Rick DeNatale

Visit the Project Mercury Wiki Site
http://www.mercuryspacecraft.com/



More information about the TriLUG mailing list