mdadm -CR $md0 -l 1 -n2 $dev0 $dev1
check resync
check raid1
-testdev $md0 1 $mdsize1a 1
+testdev $md0 1 $mdsize1a 64
mdadm -S $md0
# now with version-0.90 superblock, spare
mdadm -CR $md0 -e0.90 --level=raid1 -n3 -x2 $dev0 missing missing $dev1 $dev2
check recovery
check raid1
-testdev $md0 1 $mdsize0 1
+testdev $md0 1 $mdsize0 64
mdadm -S $md0
# now with no superblock