# create a raid5, fail and remove a drive during initial sync
# Add two more, fail and remove one
# wait for sync to complete, fail, remove, re-add

mdadm -CR $md0 -l5 -n4 $dev0 $dev1 $dev2 $dev3
check recovery
mdadm $md0 --fail $dev3
sleep 1
check nosync
check state UUU_

mdadm $md0 --add $dev4 $dev5
check recovery
check wait
mdadm $md0 --fail $dev0
mdadm $md0 --remove $dev3 $dev0
check recovery
check wait
check state UUUU

mdadm -S $md0