$ sudo mdadm -E /dev/vda1
/dev/vda1:
          Magic : a92b4efc
        Version : 00.90.00
           UUID : 1cb783f2:2f9574ca:d0bafb35:3ca9a9be
  Creation Time : Wed Apr  7 16:08:57 2010
     Raid Level : raid1
  Used Dev Size : 1464256 (1430.18 MiB 1499.40 MB)
     Array Size : 1464256 (1430.18 MiB 1499.40 MB)
   Raid Devices : 2
  Total Devices : 2
Preferred Minor : 0

    Update Time : Wed Apr  7 17:13:02 2010
          State : clean
 Active Devices : 2
Working Devices : 2
 Failed Devices : 0
  Spare Devices : 0
       Checksum : 9a6cb689 - correct
         Events : 435


      Number   Major   Minor   RaidDevice State
this     0     252        1        0      active sync

   0     0     252        1        0      active sync
   1     1     252       17        1      active sync



$ sudo mdadm -E /dev/vdb1
/dev/vdb1:
          Magic : a92b4efc
        Version : 00.90.00
           UUID : 1cb783f2:2f9574ca:d0bafb35:3ca9a9be
  Creation Time : Wed Apr  7 16:08:57 2010
     Raid Level : raid1
  Used Dev Size : 1464256 (1430.18 MiB 1499.40 MB)
     Array Size : 1464256 (1430.18 MiB 1499.40 MB)
   Raid Devices : 2
  Total Devices : 2
Preferred Minor : 0

    Update Time : Wed Apr  7 17:13:02 2010
          State : clean
 Active Devices : 2
Working Devices : 2
 Failed Devices : 0
  Spare Devices : 0
       Checksum : 9a6cb69b - correct
         Events : 435


      Number   Major   Minor   RaidDevice State
this     1     252       17        1      active sync

   0     0     252        1        0      active sync
   1     1     252       17        1      active sync