RAID 5 is one of the most common configurations in business-class storage — and one of the most misunderstood in failure.

When something goes wrong, the messages are often vague or misleading. One disk might go “foreign,” the array might disappear mid-rebuild, or two drives might drop out seemingly at once. Here’s where we translate those symptoms into clear next steps.


Technical Note TN-R5-001

Title: RAID 5 Single-Parity Failure Modes, Rebuild Breaks, and Metadata Drift

This in-depth note explains what really happens inside RAID 5 when the single-parity safety margin collapses — from latent sector errors turning a one-disk loss into an effective double-failure, to rebuild stalls, foreign-config traps, and post-power-loss metadata drift. It is the internal reference behind every RAID 5 page in this series.

Read the Full Technical Note TN-R5-001 →
/raid-5-triage/tn-r5-001