[root@cryo ~]# mdadm --examine --scan
ARRAY /dev/md1 level=raid1 num-devices=2 UUID=3abad8c0:4be0786d:c8a2b11e:99d086ae
ARRAY /dev/md0 level=raid1 num-devices=2 UUID=a7d74b17:2fd16e32:3119668d:1430566b
[root@cryo ~]# cat /proc/mdstat
Personalities : [raid1]
md2 : active raid1 hdc3[0]
      995904 blocks [2/1] [U_]

md1 : active raid1 hda4[0] hdc2[1]
      104984704 blocks [2/2] [UU]

md0 : active raid1 hda3[0] hdc1[1]
      13671168 blocks [2/2] [UU]

unused devices: <none>
[root@cryo ~]#