Reativando RAID

The RAID device appears to be inactive somehow:

# cat /proc/mdstat
Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] 
                [raid4] [raid10] 
md_d0 : inactive sda4[0](S)
      241095104 blocks

# mdadm --detail /dev/md0
mdadm: md device /dev/md0 does not appear to be active.

Code:

matt@OptimusPrime:~$ sudo mdadm --detail /dev/md0
mdadm: md device /dev/md0 does not appear to be active.
matt@OptimusPrime:~$ sudo mdadm --run /dev/md0
mdadm: failed to run array /dev/md0: Input/output error
matt@OptimusPrime:~$ sudo mdadm --detail /dev/md0
/dev/md0:
        Version : 00.90
  Creation Time : Thu Nov 24 18:01:12 2011
     Raid Level : raid5
  Used Dev Size : 1953511936 (1863.01 GiB 2000.40 GB)
   Raid Devices : 4
  Total Devices : 2
Preferred Minor : 0
    Persistence : Superblock is persistent

    Update Time : Mon Jan 21 16:40:08 2013
          State : active, degraded, Not Started
 Active Devices : 2
Working Devices : 2
 Failed Devices : 0
  Spare Devices : 0

         Layout : left-symmetric
     Chunk Size : 64K

           UUID : dc256ec9:45cdecc4:fbf2ea5a:12bfd232 (local to host OptimusPrime)
         Events : 0.90803

    Number   Major   Minor   RaidDevice State
       0       0        0        0      removed
       1       8       33        1      active sync   /dev/sdc1
       2       8       17        2      active sync   /dev/sdb1
       3       0        0        3      removed
matt@OptimusPrime:~$ 
matt@OptimusPrime:~$ sudo mdadm --examine /dev/sd[bcde]1
/dev/sdb1:
          Magic : a92b4efc
        Version : 00.90.00
           UUID : dc256ec9:45cdecc4:fbf2ea5a:12bfd232 (local to host OptimusPrime)
  Creation Time : Thu Nov 24 18:01:12 2011
     Raid Level : raid5
  Used Dev Size : 1953511936 (1863.01 GiB 2000.40 GB)
     Array Size : 5860535808 (5589.04 GiB 6001.19 GB)
   Raid Devices : 4
  Total Devices : 2
Preferred Minor : 0

    Update Time : Mon Jan 21 16:40:08 2013
          State : active
 Active Devices : 2
Working Devices : 2
 Failed Devices : 1
  Spare Devices : 0
       Checksum : ee0ec535 - correct
         Events : 90803

         Layout : left-symmetric
     Chunk Size : 64K

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

   0     0       0        0        0      removed
   1     1       8       33        1      active sync   /dev/sdc1
   2     2       8       17        2      active sync   /dev/sdb1
   3     3       0        0        3      faulty removed
/dev/sdc1:
          Magic : a92b4efc
        Version : 00.90.00
           UUID : dc256ec9:45cdecc4:fbf2ea5a:12bfd232 (local to host OptimusPrime)
  Creation Time : Thu Nov 24 18:01:12 2011
     Raid Level : raid5
  Used Dev Size : 1953511936 (1863.01 GiB 2000.40 GB)
     Array Size : 5860535808 (5589.04 GiB 6001.19 GB)
   Raid Devices : 4
  Total Devices : 2
Preferred Minor : 0

    Update Time : Mon Jan 21 16:40:08 2013
          State : active
 Active Devices : 2
Working Devices : 2
 Failed Devices : 1
  Spare Devices : 0
       Checksum : ee0ec543 - correct
         Events : 90803

         Layout : left-symmetric
     Chunk Size : 64K

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

   0     0       0        0        0      removed
   1     1       8       33        1      active sync   /dev/sdc1
   2     2       8       17        2      active sync   /dev/sdb1
   3     3       0        0        3      faulty removed
mdadm: No md superblock detected on /dev/sdd1.
/dev/sde1:
          Magic : a92b4efc
        Version : 00.90.00
           UUID : dc256ec9:45cdecc4:fbf2ea5a:12bfd232 (local to host OptimusPrime)
  Creation Time : Thu Nov 24 18:01:12 2011
     Raid Level : raid5
  Used Dev Size : 1953511936 (1863.01 GiB 2000.40 GB)
     Array Size : 5860535808 (5589.04 GiB 6001.19 GB)
   Raid Devices : 4
  Total Devices : 3
Preferred Minor : 0

    Update Time : Mon Jan 21 16:10:12 2013
          State : clean
 Active Devices : 2
Working Devices : 3
 Failed Devices : 1
  Spare Devices : 1
       Checksum : ee102159 - correct
         Events : 90796

         Layout : left-symmetric
     Chunk Size : 64K

      Number   Major   Minor   RaidDevice State
this     4       8       65        4      spare   /dev/sde1

   0     0       0        0        0      removed
   1     1       8       33        1      active sync   /dev/sdc1
   2     2       8       17        2      active sync   /dev/sdb1
   3     3       0        0        3      faulty removed
   4     4       8       65        4      spare   /dev/sde1
matt@OptimusPrime:~$

Code:

sudo -i
mdadm --stop /dev/md0
mdadm --assemble --force /dev/md0 /dev/sd[bce]1