Data Domain: Disk is Absent

Applies to:

• All Data Domain models
• All DDOS versions

Symptoms

• Disk shows as absent in system diagnostics
• Unable to add a shelf
• Unable to expand storage
• Autosupport alerts such as:
  • EVT-STORAGE-00002 - Enclosure disk is absent and should be replaced
Disk in Absent State

The Data Domain Operating System (DDOS) RAID software monitors disk performance. If communication is lost during specific I/O operations, the software may mark a disk as absent rather than failed. Common causes include:

• Faulty disk drive
• Disk not detected by DDOS
• Disk controller issues
• RAID discovery problems
• Multiple disks absent due to controller failure
• Transient firmware or software faults

1. Determine Disk State

   • Use command 'disk show hardware' to identify disks marked as (absent) or (?).
     • Disks showing full details are in a normal operating state.
     • Disks showing (absent) or (?) indicate communication issues.

     • Disk       Manufacturer/Model       Firmware  Serial No.     Capacity (enc/disk)
       ---------- -----------------------  --------  -------------- -------------------
       1.1        Hitachi HUA721050KLA330  GK6OAB0A  GTF402P6G70YRF  465.76 GiB
       ...
       ...
       2.1        (absent)                 (absent)  (absent)        (absent)
       2.2        (?)                      (?)       (?)             (?)

2. Interpret Results

   • Multiple absent disks: Refer to KB article [Data Domain: Identifying a Defective or Inactive Link Controller Card (LCC) ].
   • Single absent disk: Indicates a communication failure between the controller and disk - proceed to replacement steps.
   • Other disk states (such as, Foreign, Unknown): Refer to KB article [Data Domain: Disk State Descriptions].

3. Verify Disk Location

   • If the absent disk is in the head unit, confirm it is installed in the correct slot per the model’s Install and Setup Guide.
   • Ensure that the disk is firmly and securely seated into its slot.

4. Check for Slot Disablement Alerts

   • If the following alert is present:
     "Encl Disk has caused continuous discovery and the enclosure slot has been disabled. Replace the drive and enable the slot using CLI"
     • Replace the affected drive and reenable the slot using CLI.
     • Refer to KB article [Data Domain: Alert - Disk has caused continuous discovery and the slot has been disabled].

5. Replace Faulty Disk(s)

   • For a single absent disk in an enclosure, replace the disk.
   • If multiple disks are absent in the same enclosure, contact your Support Provider for further diagnosis.

6. Post-Replacement Validation

   • Run 'disk show hardware' or 'disk show state' to confirm the disk is now listed as in-use or spare.
     • If a disk remains absent after replacement, perform the [Data Domain: Disk Rescan Procedure]