[root@box ~]# cat /proc/mdstat
Personalities : [raid1]
md126 : active raid1 sda[1](S) sdb[0]
1953511424 blocks super external:/md0/0 [2/1] [_U]
md0 : inactive sda[1](S) sdb[0](S)
6056 blocks super external:imsm
unused devices: <none>
[root@box ~]# mdadm --details /dev/md126
mdadm: unrecognized option '--details'
Usage: mdadm --help
for help
[root@box ~]# mdadm --detail /dev/md126
/dev/md126:
Container : /dev/md0, member 0
Raid Level : raid1
Array Size : 1953511424 (1863.01 GiB 2000.40 GB)
Used Dev Size : 1953511556 (1863.01 GiB 2000.40 GB)
Raid Devices : 2
Total Devices : 2
State : clean, degraded
Active Devices : 1
Working Devices : 2
Failed Devices : 0
Spare Devices : 1
UUID : 26d07b3c:011cf12e:b11796e1:236fc2af
Number Major Minor RaidDevice State
0 0 0 0 removed
0 8 16 1 active sync /dev/sdb
1 8 0 - spare /dev/sda
