How to start a /dev/md device

[Dave Martini]

I have a raid 1 device with two disks when I stop the device in RHEL5

# mdadm --stop /dev/md4
mdadm: stopped /dev/md4

# mdadm --detail /dev/md4
mdadm: md device /dev/md4 does not appear to be active.



How does one start it up again?



# mdadm --examine /dev/sdd2
/dev/sdd2:
           Magic : a92b4efc
         Version : 00.90.00
            UUID : 7b7baf26:99e09886:0c35124d:40736950
   Creation Time : Fri Sep 12 16:17:50 2008
      Raid Level : raid1
   Used Dev Size : 71280320 (67.98 GiB 72.99 GB)
      Array Size : 71280320 (67.98 GiB 72.99 GB)
    Raid Devices : 2
   Total Devices : 2
Preferred Minor : 4

     Update Time : Fri Sep 12 16:17:50 2008
           State : active
  Active Devices : 2
Working Devices : 2
  Failed Devices : 0
   Spare Devices : 0
        Checksum : a105ab5f - correct
          Events : 0.1


       Number   Major   Minor   RaidDevice State
this     1       8       50        1      active sync   /dev/sdd2

    0     0       8       34        0      active sync   /dev/sdc2
    1     1       8       50        1      active sync   /dev/sdd2


# mdadm --examine /dev/sdc2
/dev/sdc2:
           Magic : a92b4efc
         Version : 00.90.00
            UUID : 7b7baf26:99e09886:0c35124d:40736950
   Creation Time : Fri Sep 12 16:17:50 2008
      Raid Level : raid1
   Used Dev Size : 71280320 (67.98 GiB 72.99 GB)
      Array Size : 71280320 (67.98 GiB 72.99 GB)
    Raid Devices : 2
   Total Devices : 2
Preferred Minor : 4

     Update Time : Fri Sep 12 16:17:50 2008
           State : active
  Active Devices : 2
Working Devices : 2
  Failed Devices : 0
   Spare Devices : 0
        Checksum : a105ab4d - correct
          Events : 0.1


       Number   Major   Minor   RaidDevice State
this     0       8       34        0      active sync   /dev/sdc2

    0     0       8       34        0      active sync   /dev/sdc2