How Do I Safely Replace Warning SSDs in a RAID Storage Pool?

Applicable Products

• QNAP NAS running QTS or QuTS hero
• Models with hot-swappable drive bays
• RAID groups using SSDs (RAID 1, RAID 5, RAID 6, RAID 10, etc.)

Problem Description

One or more SSDs in your RAID storage pool show a "Warning" status, indicating the SSD lifespan has been exhausted (0% life remaining) or S.M.A.R.T. errors have been detected. You want to know:

• Can you safely remove and replace a Warning drive via hot-swap?
• What is the correct procedure?
• What are the risks when multiple SSDs show Warning simultaneously?

Short Answer

Yes — a drive in Warning status can be safely hot-swapped, just like a Failed drive. You can pull the Warning SSD from the bay while the NAS is powered on, insert a new replacement SSD, and the RAID will automatically begin rebuilding. However, you must replace drives one at a time and wait for the rebuild to complete before replacing the next one.

Solution Steps

Before You Begin

1. Verify you have a current backup of all data on the RAID group. This is critical, especially when multiple drives are in Warning status.
2. Check RAID status: Ensure no other drive in the RAID group is currently in Failed or Rebuilding state.
   • Go to Storage & Snapshots → Storage/Snapshot → select the Storage Pool → view the RAID group status.
3. Identify the physical location of the Warning drive:
   • Go to Storage & Snapshots → Disks/VJBOD → find the Warning SSD → click Locate (the drive LED will blink to help you identify the correct bay).
4. Prepare the replacement SSD:
   • The new SSD must be equal to or larger than the drive being replaced.
   • Ensure the SSD is compatible with your NAS model.

Step-by-Step: Hot-Swap Replacement

Step 1: Remove the Warning SSD

1. With the NAS powered on and running, physically pull the Warning SSD out of its drive bay.
2. The NAS will emit a beep alert, and the RAID group status will change to Degraded.
3. This is expected — RAID 5 can tolerate one missing drive, RAID 6 can tolerate two.

Important: Do NOT shut down the NAS before pulling the drive. Hot-swap must be done while the system is running.

Step 2: Insert the Replacement SSD

1. Insert the new SSD into the same drive bay.
2. The NAS will automatically detect the new drive.
3. The RAID group will begin rebuilding automatically.

Step 3: Monitor the Rebuild

1. Go to Storage & Snapshots → Storage/Snapshot → select the Storage Pool.
2. The RAID group will show Rebuilding status with a progress percentage.
3. Wait for the rebuild to complete fully (100%) before proceeding to replace the next drive.

Warning: Rebuild time depends on the drive size and system load. Do not power off or restart the NAS during rebuild.

Step 4: Repeat for Additional Drives (If Needed)

If you have multiple Warning SSDs to replace:

1. Wait until the current rebuild reaches 100% and the RAID status returns to Ready/Normal.
2. Only then proceed to replace the next Warning SSD.
3. Repeat Steps 1–3 for each drive, one at a time.

After Replacement

1. Verify the RAID group status is Ready with all drives showing Good.
2. Go to Storage & Snapshots → Disks/VJBOD to confirm all new SSDs are recognized and healthy.
3. Run a RAID scrubbing (data consistency check) after all replacements are done:
   • Go to Storage & Snapshots → select the RAID group → Manage → RAID Scrubbing.

Critical Risks When Multiple SSDs Are in Warning

Risk Mitigation

1. Always have a verified backup before starting — this is the single most important precaution.
2. Replace drives during low-usage periods to reduce I/O stress on remaining Warning drives during rebuild.
3. Replace drives in order of worst health first — start with the SSD showing the most critical S.M.A.R.T. values.
4. Consider upgrading RAID level — if you frequently face multiple drive failures, RAID 6 (tolerates 2 drive failures) provides better protection than RAID 5 (tolerates only 1).

Further Reading

• How do I replace a faulty disk in a RAID group?