# 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 $mdsize1a 64 testdev $md2 1 $mdsize1a 64 testdev $md0 2 $mdsize11a 512 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 $mdsize1a 64 testdev $md0 1 $[mdsize1a+mdsize11a] 512 mdadm -Ss