Paul Smith wrote:
On 10/22/07, Michael Schwendt <mschwendt@xxxxxxxxx> wrote:
Yes, Mikkel, the disk from which I want to boot has the highest
priority in BIOS..
OK - this gets a bit tricky, because when you boot from this drive,
it is no longer hd2 - it is hd0. So Grub will be looking for its
files in the wrong place. What I would do is edit your Grub
configuration file to reflect this.
map (hd0) (hd2)
map (hd2) (hd0)
in the grub.conf boot entry would achieve that. However, before that
I would really suggest giving the "find /grub/grub.conf" command a
try, to see on which mountable partition it finds the file.
We are getting close to it! Mikkel is right. Inside the grub prompt, I
run, as suggested, the command 'find /grub/grub.conf' and I get
(h0,1). Then I run
configfile /grub/grub.conf
and I get the correct dialog panel to choose the kernel to boot, and
it goes though until a kernel panic emerges. My grub.conf file is now:
# more /mnt/sdc2/grub/grub.conf
default=0
timeout=5
splashimage=(hd0,1)/grub/splash.xpm.gz
hiddenmenu
title Fedora (2.6.22.9-91.fc7)
root (hd2,1)
kernel /vmlinuz-2.6.22.9-91.fc7 ro root=/dev/sdc2 rhgb
initrd /initrd-2.6.22.9-91.fc7.img
title Fedora (2.6.22.7-85.fc7)
root (hd2,1)
kernel /vmlinuz-2.6.22.7-85.fc7 ro root=/dev/sdc2 rhgb
initrd /initrd-2.6.22.7-85.fc7.img
where should I insert
map (hd0) (hd2)
map (hd2) (hd0)
and what should I do to avoid the kernel panic? I suspect that
something is wrong with 'root=/dev/sdc2'.
You are close. The problem may be in understanding just what root ()
is. Unless you have multiple boot partitions or are doing something
really tricky there isn't a need for multiple root commands.
root specifies the drive and partition where /boot resides. /boot
contains your kernels, ramdisks, and the various loaders (in /boot/grub)
and your boot menu, (in /boot/grub/menu.lst).
the kernel command line also uses "root". They are different. kernel
root refers to the root of your o/s' filesystem. It tells the kernel
where / starts.
Therefore you must find and load your kernel first. To eliminate
inconsistencies you may want to have only one grub root command outside
of the individual stanzas. That way it becomes the single point of
reference for grub.
default=0
timeout=5
# all grub commands are relative to /boot, so...
# on which drive/partition is /boot located?
root (hd0,1)
# ok, it's on hard drive 0's second partition
splashimage=/grub/splash.xpm.gz
hiddenmenu
title Fedora (2.6.22.9-91.fc7)
kernel /vmlinuz-2.6.22.9-91.fc7 ro root=/dev/sdc2 rhgb
initrd /initrd-2.6.22.9-91.fc7.img
The grub docs are actually pretty good. "info grub" is your friend
here. Previous advice to become familiar with cli grub is also good.
hth,
Mike Wright :m)
