[CentOS] CentOS 6.2 on partitionable mdadm RAID1 (md_d0) - kernel panic with either disk not present

Tue Jun 19 19:23:32 UTC 2012
Arun Khan <knura9 at gmail.com>

On Wed, Jun 20, 2012 at 12:11 AM,  <m.roth at 5-cent.us> wrote:
> Arun Khan wrote:
>>    Device Boot      Start         End      Blocks   Id  System
>> /dev/sda1   *           1         523     4194304   83  Linux
>> Partition 1 does not end on cylinder boundary.
>> /dev/sda2             523        1045     4194304   83  Linux
>> /dev/sda3            1045        1176     1048576   82  Linux swap /
>> Solaris
> <snip>
> Ok, I see that it's hardware 512b blocks, so you're not running into
> issues with 4k hardware blocks. I trust you installed grub on /dev/md0,
> which I assume is /dev/sda1 and /dev/sdb1?

>From the wiki instructions, there is no re-installation of GRUB, only
a couple of changes in /boot/grub/grub.conf file installed by the
regular installation on /dev/sda.   During the RAID1 creation process
the  grub from /dev/sda would mirrored into the RAID1 device and
appear on the MBR of both the disks.

As I said in the OP, I do see the grub menu with either of the disks
"unplugged"  i.e. missing.   The kernel does boot and the white
progress bar goes upto about 50% when the kernel panic occurs.  I will
turn off the splash and see what comes up on the console.   Gut
feeling --  I suspect the problem is with the initrd image created
with the "dracut"

-- Arun Khan