mdadm --detail /dev/md2
/dev/md2:
        Version : 0.90
  Creation Time : Tue Jun 28 06:55:01 2011
     Raid Level : raid1
     Array Size : 1462766336 (1395.00 GiB 1497.87 GB)
  Used Dev Size : 1462766336 (1395.00 GiB 1497.87 GB)
   Raid Devices : 2
  Total Devices : 2
Preferred Minor : 2
    Persistence : Superblock is persistent

    Update Time : Tue May 29 07:29:57 2012
          State : clean
 Active Devices : 2
Working Devices : 2
 Failed Devices : 0
  Spare Devices : 0

           UUID : bb2ab7b1:d95da6d8:776c2c25:004bd7b2
         Events : 0.448

    Number   Major   Minor   RaidDevice State
       0       8        3        0      active sync   /dev/sda3
       1       8       19        1      active sync   /dev/sdb3