CentOS - Dec 2012 - grub.conf corrupt in boot grub, fine in rescue shell

I'm trying to load CentOS 6.3 on a used server based on a Tyan Tomcat 
n3400b motherboard. The first 2 drives are configured as a RAID mirror in 
the BIOS and the remaining 4 drives are not configured but apparently still 
have RAID metadata on them. I hadn't yet figured out how to fix that but 
went ahead and loaded the OS on the mirrored set.

After pulling out a drive from the unused set, grub stopped at the grub 
prompt. I can find (hd0,0)/grub/grub.conf but when I cat it I get 
corruption with recognizable fragments. I can use setup (hd0) without issue 
but reboots keep dumping me at the grub prompt. I booted into the rescue 
environment of the minimal install CD and grub.conf looks just fine. It's 
only corrupt when I look at it from the grub boot environment. What could 
be going wrong?

It's quite likely a software RAID card and when the OS was installed it only
installed grub on one of the hard disks, the one that it thought was primary. 
I've seen this happen with quite a few software cards.  Each time the OS
booted it would load a different hard disk as primary.  If you can, try
disabling RAID on it all together.

----- Original Message -----
| I'm trying to load CentOS 6.3 on a used server based on a Tyan Tomcat
| n3400b motherboard. The first 2 drives are configured as a RAID
| mirror in
| the BIOS and the remaining 4 drives are not configured but apparently
| still
| have RAID metadata on them. I hadn't yet figured out how to fix that
| but
| went ahead and loaded the OS on the mirrored set.
| 
| After pulling out a drive from the unused set, grub stopped at the
| grub
| prompt. I can find (hd0,0)/grub/grub.conf but when I cat it I get
| corruption with recognizable fragments. I can use setup (hd0) without
| issue
| but reboots keep dumping me at the grub prompt. I booted into the
| rescue
| environment of the minimal install CD and grub.conf looks just fine.
| It's
| only corrupt when I look at it from the grub boot environment. What
| could
| be going wrong?
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| CentOS mailing list
| CentOS at centos.org
| http://lists.centos.org/mailman/listinfo/centos
| 

-- 
James A. Peltier
Manager, IT Services - Research Computing Group
Simon Fraser University - Burnaby Campus
Phone   : 778-782-6573
Fax     : 778-782-3045
E-Mail  : jpeltier at sfu.ca
Website : http://www.sfu.ca/itservices
          http://blogs.sfu.ca/people/jpeltier

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