# Recovering from defunct drives

If the defunct drives are not part of an array, contact your IBM service representative.

If a physical drive fails in an array or multiple physical drives fail in separate arrays (one physical drive per array), complete the following steps:

1. Replace each defunct physical drive. The ServeRAID controller starts the rebuild operation when it detects the removal and reinsertion of a drive that is part of an array.
   Note: (For a configuration that contains a hot-spare drive) If you replace a failed physical drive, it is not necessary to position the new physical drive on the same SCSI channel and SCSI ID as the original hot-spare drive. The replacement physical drive is automatically incorporated into the configuration as a hot-spare drive. Here is an example of how this works:
   1. The original configuration consists of a RAID level-5 logical drive composed of four physical drives. The physical drives are connected to SCSI channel 1; they are assigned SCSI IDs 0, 1, 2, and 3. SCSI ID 3 is a hot-spare drive.
   2. The physical drive at Channel 1, SCSI ID 2, fails; the logical drive enters the critical state.
   3. The hot-spare drive at Channel 1, SCSI ID 3, is rebuilt into the array.
   4. You remove the failed physical drive at Channel 1, SCSI ID 2, and replace it with a new physical drive. The new physical drive at Channel 1, SCSI ID 2, is automatically assigned to be a hot-spare drive.
2. If a rebuild operation is in progress, wait until the rebuild is complete. Otherwise, go to step 3.
   Note: If you are replacing multiple defunct drives, you must wait for each rebuild operation to complete before starting subsequent rebuild operations.
3. Verify the cables, physical drives, and controllers are installed properly.
4. Attempt to rebuild the defunct physical drive by performing a hot-swap rebuild.
5. If the hot-swap rebuild fails, contact your IBM service representative.

## More information

- Rebuilding a defunct drive
- Rebuilding a hot-swap drive
- Changing the rebuild rate (action)
- Unblocking a logical drive (action)
- RAID level-0
- RAID level-1
- RAID level-5

Glossary | Contents

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