# create two raid1s, build a raid0 on top, then
# tear it down and get auto-assemble to rebuild it.

mdadm -CR $md1 -l1 -n2 $dev0 $dev1  --homehost=testing
mdadm -CR $md2 -l1 -n2 $dev2 $dev3  --homehost=testing
mdadm -CR $md0 -l0 -n2 $md1 $md2  --homehost=testing

mdadm -Ss
mdadm -As -c /dev/null --homehost=testing -vvv
testdev $md1 1 $mdsize0 64
testdev $md2 1 $mdsize0 64
testdev $md0 2 $mdsize00 64
mdadm -Ss

mdadm --zero-superblock $dev0 $dev1 $dev2 $dev3
## Now the raid0 uses one stacked and one not
mdadm -CR $md1 -l1 -n2 $dev0 $dev1  --homehost=testing
mdadm -CR $md0 -l0 -n2 $md1 $dev2  --homehost=testing
mdadm -Ss
mdadm -As -c /dev/null --homehost=testing -vvv
testdev $md1 1 $mdsize0 64
testdev $md0 1 $[mdsize0+mdsize00] 64