hoferr@media-server:~$ sudo mdadm --detail /dev/md0
/dev/md0:
        Version : 0.90
  Creation Time : Wed Dec 22 02:13:21 2010
     Raid Level : raid5
     Array Size : 4395411264 (4191.79 GiB 4500.90 GB)
  Used Dev Size : 1465137088 (1397.26 GiB 1500.30 GB)
   Raid Devices : 4
  Total Devices : 4
Preferred Minor : 0
    Persistence : Superblock is persistent

    Update Time : Wed Apr 18 11:16:32 2012
          State : clean
 Active Devices : 4
Working Devices : 4
 Failed Devices : 0
  Spare Devices : 0

         Layout : left-symmetric
     Chunk Size : 64K

           UUID : 426c0b3a:41ce01ea:d14afcea:0399e8b7
         Events : 0.48731

    Number   Major   Minor   RaidDevice State
       0       8       49        0      active sync   /dev/sdd1
       1       8       65        1      active sync   /dev/sde1
       2       8       17        2      active sync   /dev/sdb1
       3       8       33        3      active sync   /dev/sdc1

hoferr@media-server:~$ sudo mdadm --zero-superblock /dev/sdd
mdadm: Couldn't open /dev/sdd for write - not zeroing

hoferr@media-server:~$ sudo mdadm --stop /dev/md0
mdadm: stopped /dev/md0

hoferr@media-server:~$ sudo mdadm --zero-superblock /dev/sdd
mdadm: Unrecognised md component device - /dev/sdd

hoferr@media-server:~$ sudo mdadm --zero-superblock /dev/sdd1
hoferr@media-server:~$ sudo mdadm --zero-superblock /dev/sde1
hoferr@media-server:~$ sudo mdadm --zero-superblock /dev/sdb1
hoferr@media-server:~$ sudo mdadm --zero-superblock /dev/sdc1

hoferr@media-server:~$ sudo mdadm --create --verbose /dev/md0 --auto=yes --assume-clean --level=5 --raid-devices=4 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1
mdadm: layout defaults to left-symmetric
mdadm: chunk size defaults to 512K
mdadm: layout defaults to left-symmetric
mdadm: layout defaults to left-symmetric
mdadm: layout defaults to left-symmetric
mdadm: layout defaults to left-symmetric
mdadm: layout defaults to left-symmetric
mdadm: size set to 1465135616K
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md0 started.

hoferr@media-server:~$ sudo mdadm --assemble /dev/md0 --update=resync

hoferr@media-server:~$ sudo mdadm --detail /dev/md0
/dev/md0:
        Version : 1.2
  Creation Time : Wed Apr 18 16:07:12 2012
     Raid Level : raid5
     Array Size : 4395406848 (4191.79 GiB 4500.90 GB)
  Used Dev Size : 1465135616 (1397.26 GiB 1500.30 GB)
   Raid Devices : 4
  Total Devices : 4
    Persistence : Superblock is persistent

    Update Time : Wed Apr 18 16:07:12 2012
          State : clean
 Active Devices : 4
Working Devices : 4
 Failed Devices : 0
  Spare Devices : 0

         Layout : left-symmetric
     Chunk Size : 512K

           Name : media-server:0  (local to host media-server)
           UUID : a6c5c588:47d9ce20:7cc3ca49:0d0bc7db
         Events : 0

    Number   Major   Minor   RaidDevice State
       0       8       17        0      active sync   /dev/sdb1
       1       8       33        1      active sync   /dev/sdc1
       2       8       49        2      active sync   /dev/sdd1
       3       8       65        3      active sync   /dev/sde1

hoferr@media-server:~$ sudo mount /dev/md0 test/
mount: you must specify the filesystem type

hoferr@media-server:~$ sudo mount -tjfs /dev/md0 test/
mount: wrong fs type, bad option, bad superblock on /dev/md0,
       missing codepage or helper program, or other error
       In some cases useful info is found in syslog - try
       dmesg | tail  or so

hoferr@media-server:~$ dmesg | tail
[ 1211.116702] mdadm: sending ioctl 1261 to a partition!
[ 1211.116707] mdadm: sending ioctl 1261 to a partition!
[ 1322.605543] mdadm: sending ioctl 1261 to a partition!
[ 1322.605549] mdadm: sending ioctl 1261 to a partition!
[ 1381.917490] mdadm: sending ioctl 800c0910 to a partition!
[ 1381.917495] mdadm: sending ioctl 800c0910 to a partition!
[ 1381.917662] mdadm: sending ioctl 800c0910 to a partition!
[ 1381.917668] mdadm: sending ioctl 800c0910 to a partition!
[ 1385.126808] mdadm: sending ioctl 1261 to a partition!
[ 1385.126814] mdadm: sending ioctl 1261 to a partition!

hoferr@media-server:~$ sudo fdisk -l /dev/md0

Disk /dev/md0: 4500.9 GB, 4500896612352 bytes
2 heads, 4 sectors/track, 1098851712 cylinders
Units = cylinders of 8 * 512 = 4096 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 524288 bytes / 1572864 bytes
Disk identifier: 0x00000000

Disk /dev/md0 doesn't contain a valid partition table