# create a simple raid5 set mdadm -CfR $md0 -e 0.90 -l 5 -n3 $dev0 $dev1 $dev2 check resync testdev $md0 2 $mdsize0 512 mdadm -S $md0 # now with version-1 superblock mdadm -CR $md0 -e1 --level=raid5 -n4 $dev0 $dev1 $dev2 $dev3 check recovery testdev $md0 3 $mdsize1 512 mdadm -S $md0 # now same again with explicit layout for lo in la ra left-symmetric right-symmetric do mdadm -CfR $md0 -l 5 -p $lo -n3 $dev0 $dev1 $dev2 check resync ; check raid5 testdev $md0 2 $mdsize1 512 mdadm -S $md0 # now with version-1 superblock mdadm -CR $md0 -e1 --level=raid5 --layout $lo -n4 $dev0 $dev1 $dev2 $dev3 check recovery ; check raid5 testdev $md0 3 $mdsize1 512 mdadm -S $md0 done exit 0