When One Stripe Group Fails, Both Logics Collapse — What RAID 50 Failures Really Mean

RAID 50 combines RAID 5 groups under RAID 0 striping — which means when one group falters, the upper-level stripe loses its foundation.

That’s why RAID 50 failures often look worse than RAID 5:

  • Volumes go offline even when “only one drive failed”
  • Rebuilds stall at 0%
  • One group appears healthy, the other disappears
  • Power events cause one parity group to revert or desync
  • Foreign configs don’t match across groups
  • Drives show good SMART status, but the array won’t mount

This page is your safe starting point before any rebuild, import, or metadata change.

DIY Stops Here — But You Don’t Have to Guess

Start with the RAID-50-specific triage pages that best match your symptoms:

Then:

Run JeannieLite™, ADR’s safe read-only diagnostic tool.
It captures stripe-group identity, parity signatures, cache state, and controller metadata — without touching data.

Technical Note TN-R50-001 — RAID 50 Failure Modes, Group Misalignment, and Cross-Stripe Metadata Drift

This technical note explains what actually happens inside a RAID 50 controller when one stripe group goes dark, parity fails on a single subgroup, or foreign configs disagree.
It’s the backbone that supports all RAID-50 triage pages.