Someone

sinope:/etc/mdadm# mdadm -R /dev/md1
mdadm: failed to run array /dev/md1: Input/output error
sinope:/etc/mdadm# mdadm -D /dev/md1
/dev/md1:
        Version : 01.00.03
  Creation Time : Thu Dec  7 22:48:04 2006
     Raid Level : raid5
    Device Size : 312571136 (298.09 GiB 320.07 GB)
   Raid Devices : 6
  Total Devices : 1
Preferred Minor : 1
    Persistence : Superblock is persistent

    Update Time : Thu Feb 15 16:09:47 2007
          State : clean, degraded, Not Started
 Active Devices : 1
Working Devices : 1
 Failed Devices : 0
  Spare Devices : 0

         Layout : left-symmetric
     Chunk Size : 64K

  Delta Devices : 2, (4->6)

           Name : 1
           UUID : 52c3f68b:130e4a5b:9ed0c306:12e0a06c
         Events : 181874

    Number   Major   Minor   RaidDevice State
       0       0        0        0      removed
       1       0        0        1      removed
       2       0        0        2      removed
       3       0        0        3      removed
       6       8       80        4      active sync   /dev/sdf
       5       0        0        5      removed