LVM on RAID - lost the RAID

[Jason Bleazard <jason.debian@bleazard.net>]

I've just recently noticed that my LVM on RAID setup is no longer using the 
RAID.  It appears that LVM picked one partition out of the mirror.  I'm not 
sure exactly when this happened.  I thought mdadm was configured to notify me 
of any problems, but it didn't.  I happened to check my mdstat and noticed 
that the array was gone (it definitely was working fine at one point).

Fortunately, I have two arrays, md0 for the root (no LVM), and md1 for the LVM 
volumes, so I can at least do some maintenance on the system with md1 
removed.  md0 still works fine.

I did some searching, and apparently I need to set md_component_detection to 1 
in /etc/lvm/lvm.conf.

Unfortunately, this didn't magically fix my problem.  After that, I can't see 
any of the filesystems in the md1 array.

Any pointers or advice on how to get md1 back?  I'm more than happy to post 
any relevant information, just let me know what you would need to see.

Thanks in advance,
Jason