On Tue, 03 Apr 2012 15:53:01 +1000
NeilBrown [off-list ref] wrote:

To reverse a partial reshape which changes the number of devices
you can stop the array and re-assemble with the raid-disks numbers
reversed and it will undo.

Unfortunately this does not seem to work:

# mdadm --assemble --raid-disks=5 --backup-file=/mnt/scratch/backup-file /dev/md0 /dev/sdb1 /dev/sdc1 /dev/sde1 /dev/sdd1 /dev/sdf1
mdadm:option --raid-disks not valid in assemble mode

-- 
With respect,
Roman

~~~~~~~~~~~~~~~~~~~~~~~~~~~
"Stallman had a printer,
with code he could not see.
So he began to tinker,
and set the software free."