mdadm: too-old timestamp on backup-metadata

[William Heaton <acroporas@gmail.com>]

*I am not on the mailing list.  Please include acroporas@gmail.com in 
any replies.*

I had a 4-disk RAID5.  I added a 5th disk and at the same time converted 
it to RAID6.

Things started out looking good, but after about a day, the reshape 
appeared to have stalled.  After waiting more than 24 hours without 
seeing any progress I rebooted the computer.  Immediately before the 
rebooting the array was running and all data was accessible.  But after 
reboot, the array would not start.  Can anyone help me get the array 
restarted?  Thanks

~$ uname -a
Linux pholidochromis 2.6.32-24-generic #39-Ubuntu SMP Wed Jul 28 
05:14:15 UTC 2010 x86_64 GNU/Linux

~$ mdadm --version
mdadm - v3.1.2 - 10th March 2010


~$ sudo mdadm --assemble /dev/md0 /dev/sd[bcdel]1  -vv -f --backup-file 
/media/Backup/rb
mdadm: looking for devices for /dev/md0
mdadm: /dev/sdb1 is identified as a member of /dev/md0, slot 4.
mdadm: /dev/sdc1 is identified as a member of /dev/md0, slot 2.
mdadm: /dev/sdd1 is identified as a member of /dev/md0, slot 0.
mdadm: /dev/sde1 is identified as a member of /dev/md0, slot 1.
mdadm: /dev/sdl1 is identified as a member of /dev/md0, slot 3.
mdadm:/dev/md0 has an active reshape - checking if critical section 
needs to be restored
mdadm: too-old timestamp on backup-metadata on /media/Backup/rb
mdadm: Failed to find backup of critical section
mdadm: Failed to restore critical section for reshape, sorry.