root@ubuntu:~# mdadm --examine /dev/sdc1
/dev/sdc1:
          Magic : a92b4efc
        Version : 00.90.00
           UUID : fd84f8bc:65323cbc:e368bf24:bd0fce41 (local to host ubuntu)
  Creation Time : Tue Jan 22 09:33:52 2008
     Raid Level : raid5
  Used Dev Size : 19542976 (18.64 GiB 20.01 GB)
     Array Size : 58628928 (55.91 GiB 60.04 GB)
   Raid Devices : 4
  Total Devices : 4
Preferred Minor : 0

    Update Time : Sat Feb 16 20:19:09 2008
          State : clean
 Active Devices : 4
Working Devices : 4
 Failed Devices : 0
  Spare Devices : 0
       Checksum : 3cd2c501 - correct
         Events : 0.46

         Layout : left-symmetric
     Chunk Size : 32K

      Number   Major   Minor   RaidDevice State
this     1       8       33        1      active sync   /dev/sdc1

   0     0       8        1        0      active sync   /dev/sda1
   1     1       8       33        1      active sync   /dev/sdc1
   2     2       8       17        2      active sync   /dev/sdb1
   3     3       8       49        3      active sync   /dev/sdd1
root@ubuntu:~# mdadm --examine /dev/sdd1
/dev/sdd1:
          Magic : a92b4efc
        Version : 00.90.00
           UUID : fd84f8bc:65323cbc:e368bf24:bd0fce41 (local to host ubuntu)
  Creation Time : Tue Jan 22 09:33:52 2008
     Raid Level : raid5
  Used Dev Size : 19542976 (18.64 GiB 20.01 GB)
     Array Size : 58628928 (55.91 GiB 60.04 GB)
   Raid Devices : 4
  Total Devices : 4
Preferred Minor : 0

    Update Time : Sat Feb 16 20:23:19 2008
          State : clean
 Active Devices : 1
Working Devices : 1
 Failed Devices : 2
  Spare Devices : 0
       Checksum : 3cd2c650 - correct
         Events : 0.60

         Layout : left-symmetric
     Chunk Size : 32K

      Number   Major   Minor   RaidDevice State
this     3       8       49        3      active sync   /dev/sdd1

   0     0       0        0        0      removed
   1     1       0        0        1      faulty removed
   2     2       0        0        2      faulty removed
   3     3       8       49        3      active sync   /dev/sdd1
root@ubuntu:~# mdadm --examine /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1
/dev/sda1:
          Magic : a92b4efc
        Version : 00.90.00
           UUID : fd84f8bc:65323cbc:e368bf24:bd0fce41 (local to host ubuntu)
  Creation Time : Tue Jan 22 09:33:52 2008
     Raid Level : raid5
  Used Dev Size : 19542976 (18.64 GiB 20.01 GB)
     Array Size : 58628928 (55.91 GiB 60.04 GB)
   Raid Devices : 4
  Total Devices : 4
Preferred Minor : 0

    Update Time : Sat Feb 16 20:19:09 2008
          State : clean
 Active Devices : 4
Working Devices : 4
 Failed Devices : 0
  Spare Devices : 0
       Checksum : 3cd2c4df - correct
         Events : 0.46

         Layout : left-symmetric
     Chunk Size : 32K

      Number   Major   Minor   RaidDevice State
this     0       8        1        0      active sync   /dev/sda1

   0     0       8        1        0      active sync   /dev/sda1
   1     1       8       33        1      active sync   /dev/sdc1
   2     2       8       17        2      active sync   /dev/sdb1
   3     3       8       49        3      active sync   /dev/sdd1
/dev/sdb1:
          Magic : a92b4efc
        Version : 00.90.00
           UUID : fd84f8bc:65323cbc:e368bf24:bd0fce41 (local to host ubuntu)
  Creation Time : Tue Jan 22 09:33:52 2008
     Raid Level : raid5
  Used Dev Size : 19542976 (18.64 GiB 20.01 GB)
     Array Size : 58628928 (55.91 GiB 60.04 GB)
   Raid Devices : 4
  Total Devices : 4
Preferred Minor : 0

    Update Time : Sat Feb 16 20:19:09 2008
          State : clean
 Active Devices : 4
Working Devices : 4
 Failed Devices : 0
  Spare Devices : 0
       Checksum : 3cd2c4f3 - correct
         Events : 0.46

         Layout : left-symmetric
     Chunk Size : 32K

      Number   Major   Minor   RaidDevice State
this     2       8       17        2      active sync   /dev/sdb1

   0     0       8        1        0      active sync   /dev/sda1
   1     1       8       33        1      active sync   /dev/sdc1
   2     2       8       17        2      active sync   /dev/sdb1
   3     3       8       49        3      active sync   /dev/sdd1
/dev/sdc1:
          Magic : a92b4efc
        Version : 00.90.00
           UUID : fd84f8bc:65323cbc:e368bf24:bd0fce41 (local to host ubuntu)
  Creation Time : Tue Jan 22 09:33:52 2008
     Raid Level : raid5
  Used Dev Size : 19542976 (18.64 GiB 20.01 GB)
     Array Size : 58628928 (55.91 GiB 60.04 GB)
   Raid Devices : 4
  Total Devices : 4
Preferred Minor : 0

    Update Time : Sat Feb 16 20:19:09 2008
          State : clean
 Active Devices : 4
Working Devices : 4
 Failed Devices : 0
  Spare Devices : 0
       Checksum : 3cd2c501 - correct
         Events : 0.46

         Layout : left-symmetric
     Chunk Size : 32K

      Number   Major   Minor   RaidDevice State
this     1       8       33        1      active sync   /dev/sdc1

   0     0       8        1        0      active sync   /dev/sda1
   1     1       8       33        1      active sync   /dev/sdc1
   2     2       8       17        2      active sync   /dev/sdb1
   3     3       8       49        3      active sync   /dev/sdd1
/dev/sdd1:
          Magic : a92b4efc
        Version : 00.90.00
           UUID : fd84f8bc:65323cbc:e368bf24:bd0fce41 (local to host ubuntu)
  Creation Time : Tue Jan 22 09:33:52 2008
     Raid Level : raid5
  Used Dev Size : 19542976 (18.64 GiB 20.01 GB)
     Array Size : 58628928 (55.91 GiB 60.04 GB)
   Raid Devices : 4
  Total Devices : 4
Preferred Minor : 0

    Update Time : Sat Feb 16 20:23:19 2008
          State : clean
 Active Devices : 1
Working Devices : 1
 Failed Devices : 2
  Spare Devices : 0
       Checksum : 3cd2c650 - correct
         Events : 0.60

         Layout : left-symmetric
     Chunk Size : 32K

      Number   Major   Minor   RaidDevice State
this     3       8       49        3      active sync   /dev/sdd1

   0     0       0        0        0      removed
   1     1       0        0        1      faulty removed
   2     2       0        0        2      faulty removed
   3     3       8       49        3      active sync   /dev/sdd1
root@ubuntu:~#