[techtalk] Problems booting from RAID

[Magni Onsoien]

Jane Dawson:
> I decided to set up a completely RAID-based system using two identical IDE
> hard disks, each with 3 partitions (boot, swap and data). 
> 
> The setup is
> 
> hda1 and hdc1 = 800Mb boot
> hda2 and hdc2 = 128Mb swap
> hda3 and hdc3 = 3Gb data
> 
> I'm using kernel 2.4.0-test5 with Ingo's 'dangerous' raidtools and have
> successfully managed to get the data partitions running in RAID-1 as
> /dev/md2.
> 
> Great :)
> 
> But I am having appalling problems in getting the machine to boot from
> RAID! I've been through the Software-RAID-HOWTO so many times I can almost
> recite it, but still things aren't going as they should.
> 
> Does anyone have any pointers as to where I'm going wrong? At the moment,
> all six paritions are set in 'cfdisk' to type 'fd'. What should I put in
> lilo.conf, etc. ?
> 
> Any help / common problems would be most appreciated because this thing is
> driving me crazy!

Could you post your lilo.conf? What version of LILO are you using?

I installed RH6.2 on one IDE-disk last week, then "upgraded" to RAID-1
with another disk afterwords. I mostly followed Boot+Root+Raid-HOWTO
about how to move stuff around and marking disks as failed/working etc.

I then sat 'boot = /dev/md0' (which is my root-partition) in lilo.conf
and then using /dev/md0 as root-partition further down in lilo.conf (if
you have a separate /boot-partition, you should use that device in the
"boot =" statement, and whereever your rootfilesystem is in the
root-statement for the image.

It is very important that you make a initrd (with mkinitrd) so the
kernel know the RAID-modules if you compiled them as modules. I used
mkinitrd --with=raid1 initrd-2.2.16 2.2.16 to make a suitable initrd.

I then ran /sbin/lilo as usual and booted. You MUST have a new
lilo-version with some patches applied (read the above HOWTO + the
Software-RAID-HOWTO), but if you have RedHat 6.2 (or a similar system
where RH6.2-RPMs can be used, I guess) the patches are already applied
(the kernel also contains RAID-patches). This is LILO version 21.


Magni :)
-- 
ulimit is good for you.