I migrated a Xen PVM to VMware. The VM also had an MD-RAID1 using metadata
version 1.2.
I copied the blocks from the old disks to the new ones using dd via SSH.
When examining the disks on the new VM using "mdadm -E /dev/sdc", it reports a
"clean" state and a "correct" checksum. For the other disk as well.

Using "mdadm -v -A /dev/md1" it found both members for md1 and the
corresponding slots, but fails to assemble saying "Invalid argument".

Looking in syslog I see the kernel complains "md: sdc does not have a valid
v1.2 superblock, not importing!"

My guess is that new new disks are a bit larger than the original ones, but
still:
Shouldn't "mdadm -E" complain if the kernel would not accept the disk?
Or should the kernel accept what mdadm accepts?