I have an issue with a RAID1 array on my Sparc T5120. The superblocks of 3 
partitions are attached. The array was created as degraded RAID1 on sda2, then 
extended to sdb2 and sdc2, and then sda2 was removed from the array. I'm not 
entirely sure about the mdadm version used to extend the array, but it is 
likely 3.4 (current Gentoo stable).

From what I see the super_offset is written in big endian, which is consistent 
with the error message about super_offset being wrong when I run "mdadm -Asv". 
My luck is that the system on sda2 is still valid, so after reboot I ended up 
in an old copy of my data.

My plan is to change the GUID on sda2 and fix the super_offset on sd[bc]2, then 
reboot and hope the array(s) come up correctly.

Any thoughts on this, anything you want to test me, anything to make my life 
easier instead of poking with a hexeditor on the raw partitions?

Eike