nas ~ #  mdadm --create --verbose /dev/md4 --level=5 --raid-devices=3 missing /dev/sde4 /dev/sdf4
mdadm: layout defaults to left-symmetric
mdadm: layout defaults to left-symmetric
mdadm: chunk size defaults to 512K
mdadm: size set to 2876681216K
mdadm: automatically enabling write-intent bitmap on large array
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md4 started.