RAID 6 Virtual Disk Not Detected After Power Loss
The Vanishing Array — When RAID 6 Forgets It Exists
A routine restart turns into silence — no virtual disk, no array, just raw drives. You feel the floor drop out.
This isn’t a physical failure but a metadata reset. Controllers sometimes lose their cache state after a power cut or battery drain, forgetting which drive belongs where. The data remains, but the map is gone.
Most cases trace back to a cleared NVRAM log or an incomplete write-back cache flush during shutdown. That partial epoch makes the array look foreign or missing entirely.
Don’t initialize. Don’t create a new array. Read the metadata first — it will tell you if the drives still share a common parity signature or if the controller needs a foreign config rebuild.
Diagnostic Overview
- Array Type: RAID 6 Virtual Disk
- Symptoms: Array missing after power loss / BIOS does not list virtual disk
- Likely Cause: Controller cache battery failure or metadata desync in NVRAM
- Immediate Action: Capture controller logs; do not initialize; analyze with JeannieLite™ RAID Inspector
- Risk Level: Critical — Do not overwrite metadata or rebuild until layout verified
What You See:
- “Foreign Configuration Detected” message at boot
- Options to Import or Clear config
- Drives show up as present, but no volume is accessible
What It Likely Means:
- Controller metadata got out of sync after the outage
- RAID 6 parity or order info may differ from what the controller expects
- One or more drives may have timed out and rejoined with stale metadata
What NOT To Do:
- Don’t rush to “Import Foreign Config” without analysis
- Don’t “Clear and recreate” unless you’re 100% certain of drive order
- Don’t guess which config is correct — controller logic isn’t always right
What You CAN Do:
- Pause and label each drive’s port and physical bay
- Use JeannieLite to capture both the foreign and onboard config maps
- Compare metadata versioning to determine safest path
Foreign configs are common after RAID 6 power events — but choosing the wrong one can split parity and corrupt the array.