$ mdadm -E /dev/sdb5
    /dev/sdb5:
              Magic : a92b4efc
            Version : 1.2
        Feature Map : 0x0
         Array UUID : 6fa3143c:344c9ebe:3d472d13:b7c7c298
               Name : DiskStation:2  (local to host DiskStation)
      Creation Time : Fri Nov 16 11:10:39 2012
         Raid Level : raid1
       Raid Devices : 1
    
     Avail Dev Size : 5851063680 (2790.00 GiB 2995.74 GB)
         Array Size : 5851063296 (2790.00 GiB 2995.74 GB)
      Used Dev Size : 5851063296 (2790.00 GiB 2995.74 GB)
        Data Offset : 2048 sectors
       Super Offset : 8 sectors
              State : clean
        Device UUID : 1c8ec8f2:31d18ca0:519f6ebb:f8e2755d
    
        Update Time : Fri Nov 30 18:19:15 2012
           Checksum : 7129e744 - correct
             Events : 2
    
    
       Device Role : Active device 0
       Array State : A ('A' == active, '.' == missing)