mdadm --misc --detail /dev/md0 /dev/md1

mdadm (text/plain), 1.40 KB, created by Florian Philipp on 2008-07-28 19:18:01 UTC

/dev/md0:
        Version : 00.90.03
  Creation Time : Thu Jul 24 18:35:15 2008
     Raid Level : raid0
     Array Size : 312576512 (298.10 GiB 320.08 GB)
   Raid Devices : 2
  Total Devices : 2
Preferred Minor : 0
    Persistence : Superblock is persistent

    Update Time : Mon Jul 28 21:16:24 2008
          State : active
 Active Devices : 2
Working Devices : 2
 Failed Devices : 0
  Spare Devices : 0

     Chunk Size : 64K

           UUID : 8663eb4d:99f7bb89:340b9e41:57f6fcb4
         Events : 0.3

    Number   Major   Minor   RaidDevice State
       0       8        1        0      active sync   /dev/sda1
       1       8       17        1      active sync   /dev/sdb1
/dev/md1:
        Version : 00.90.03
  Creation Time : Thu Jul 24 18:36:26 2008
     Raid Level : raid1
     Array Size : 312576448 (298.10 GiB 320.08 GB)
  Used Dev Size : 312576448 (298.10 GiB 320.08 GB)
   Raid Devices : 2
  Total Devices : 1
Preferred Minor : 1
    Persistence : Superblock is persistent

    Update Time : Mon Jul 28 21:16:38 2008
          State : clean, degraded
 Active Devices : 1
Working Devices : 1
 Failed Devices : 0
  Spare Devices : 0

           UUID : f7d185c2:c9c69a20:7fbe18e8:3b261a1d
         Events : 0.190

    Number   Major   Minor   RaidDevice State
       0       9        0        0      active sync   /dev/disk/by-id/md-uuid-8663eb4d:99f7bb89:340b9e41:57f6fcb4
       1       0        0        1      removed