nas ~ # cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4]
md4 : active raid5 sdf4[2] sde4[1]
      5753362432 blocks super 1.2 level 5, 512k chunk, algorithm 2 [3/2] [_UU]
      bitmap: 0/22 pages [0KB], 65536KB chunk