Red Hat, Raid and Grub

[Cormac McGaughey]

Hi,
I've seen a few questions about this but no answers. Here is the 
problem:

In redhat if you are booting to a raid device and you are using grub 
you will find some strangeness. You will see:

o You update grub, and it doesn't change at boot up
o Grub breaks, but everything seems ok when you look in /boot/grub

I had these issued. I was running redhat 7.3, with a Raid 1 array, 
and ext3. I updated my kernel and grub successfully booted the old 
kernel that no longer existed.

After much work I discovered something nasty. When you boot from a 
raid device in redhat, /boot is not really /boot. To fix your grub 
issues you have to do this (change drives to refect your own 
settings):

init 1
...
umount /dev/md0
mount /dev/hda1 /tmp
cd /tmp/boot

You'll now be in the /boot that is used at boot time. You can fix any 
grub problems you had in this version of /boot, and they will work. I 
don't think /dev/md0/boot is ever used at all.

This should allow you to solve most raid grub issues.

Cormac
--
Cormac McGaughey
Computer Support Specialist
Institute of Technology
Harmon 307
University of Washington Tacoma
1900 Commerce St. Box 358426
Phone: 253-692-4648