Difference between revisions of "DegradedPool"

Revision as of 19:18, 1 April 2014

In case you have a degraded pool due to corrupted data on one drive, zpool status will show something like this:

sudo zpool status
 pool: tank
     id: 4167705491194610230
  state: DEGRADED
 status: One or more devices contains corrupted data.
 action: The pool can be imported despite missing or damaged devices.  The
        fault tolerance of the pool may be compromised if imported.
   see: http://zfsonlinux.org/msg/ZFS-8000-4J
 config:
 
        tank                                      DEGRADED
          fs                                        DEGRADED
            disk1s2                             ONLINE
            disk2s2                             ONLINE
            2735026605872377559   FAULTED  corrupted data
            disk4s2                             ONLINE

Now, look into DiskUtility and find the disk number of the disk which is missing. (In our case disk3). If you are certain that the corrupted data was not due to a bad disk, (for example if just the labels were messed up), we would like to delete the partition table of that disk and afterwards format the drive.

If the disk is faulty, take a new disk and skip this step, going directly to the format.

sudo gpt destroy disk3

Now, format in DiskUtility as one partition, using GUID partition table, as hfs+ and look up the new disk partition id in the lower part of the DiskUtility-window. (in our case disk3s2) Replace the now missing drive in the pool with the newly formatted disk:

sudo zpool replace tank 2735026605872377559 /dev/disk3s2

The number you see is the one which you saw above at the position of the faulted drive in sudo zpool status.

The system now starts resilvering the drive. This takes a long time. With sudo zpool status you can see the progress.