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

Thu Jun 21 18:10:07 UTC 2012
Scott Silva <ssilva at sgvwater.com>

on 6/20/2012 11:34 PM Arun Khan spake the following:
> 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
> <copy-paste>
> 
> 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>
> 
> </copy-paste>
> 
> 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
> 
> Personalities:
> 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
> 
Just a shot in the dark... DO all the fstab entries call out md devices?