### A drive is Defunct on controller [number], channel [number], SCSI ID [number].

Explanation: Error in communication between the drive and the adapter while the adapter was attempting to validate RAID configuration of the drive.

Action:

- Check in the following order:
  - Power to external enclosures, connections
  - Cables for proper seating
  - Damage or bent or pushed pins, termination (for non-back plane systems), back planes, drives and adapter.

  If no connection problems can be identified, then the replacement order for parts is termination (for non-back plane systems), cables, drives, backplanes, and adapter. Before replacing a drive or adapter ensure that the they are updated with the latest firmware and still fail.
  Note: If multiple drives are marked defunct within the same time period, check cables and back planes.