RAID1, Disk Mirroring: Not failing the last device correctly

Solution Verified - Updated -


  • In RAID 1 configuration, when both the disks are failed, state of only one of them is shown as faulty in the output of mdadm --detail /dev/mdX command, and the state of last failed disk is still displayed as active-sync.

    $ mdadm --fail /dev/md0 /dev/sdf
    mdadm: set /dev/sdf faulty in /dev/md0
    $ mdadm --detail /dev/md0
            Version : 00.90.03
      Creation Time : Mon Aug 22 22:36:06 2011
        Raid Level : raid1
       Number  Major  Minor  RaidDevice State
            0      0       0        0      removed
            1      8      80        1      active sync  /dev/sdf  <-- Still the device status is shown as Active Sync
            2      8     112        -      faulty spare  /dev/sdh <-- Device /dev/sdh is already Faulty


  • Red Hat Enterprise Linux 5.

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