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

Thu Jun 21 06:34:11 UTC 2012
Arun Khan <knura9 at gmail.com>

On Thu, Jun 21, 2012 at 10:09 AM, Rob Kampen
<rkampen at reaching-clients.com> wrote:
.... snip ....

> sounds like the mirror is not in synch - when it is running with both
> drives, what does
>>cat /proc/mdstat

System boots up fully functional with both disks

root at centos62-raid1 ~ >
# cat /proc/mdstat
Personalities : [raid1]
md_d0 : active raid1 sda[0] sdb[1]
      10485696 blocks [2/2] [UU]

unused devices: <none>


Both disks are in sync.

Anyways, even if they were out of sync the system should boot with the
"disk" that is in "U" state but it does not.

System boots up in rdshell (failed mode) with one of the disks disconnected.

<cat /proc/mdstat>

# cat /proc/mdstat

md_d0: inactive sda[0] (S)
             10485696 blocks

</cat /proc/mdstat>

I do not know the internal workings of "dracut" but  the problem seems
to be within it (gut feeling).

-- Arun Khan