On Wed, Dec 14, 2011 at 1:41 PM, Troy Telford [off-list ref] wrote:
<SNIP>

Unfortunately, I'm not sure how to get my current superblock version:
$ sudo mdadm --examine /dev/md2
mdadm: No md superblock detected on /dev/md2.

use --detail instead:

c2stable ~ # mdadm --detail /dev/md126 | grep Version
        Version : 0.90
c2stable ~ #

HTH,
Mark