RAID 5 tolerates one failed disk. When a second disk fails, or a rebuild fails or is forced onto a stale disk, the array goes offline — but it's usually recoverable by reconstructing the parity and disk order in our lab. Do NOT force a rebuild, re-add the removed disk, or re-initialise. Power the array down, label the disk order, and call an engineer.
What to do right now (safe steps)
Stop it before an automatic rebuild runs onto a degraded disk and overwrites parity.
Disk order is critical for reconstruction. Note which drive came from which slot before removing anything.
Don't rebuild, re-add the failed disk, initialise, or run repair — these overwrite recoverable data.
Book a priority diagnosis. Call us or start online.
RAID 5 states: healthy → degraded → offline
All disks online. Data and parity distributed across the array.
Still running on parity — but with no redundancy left. Back up now and replace the disk carefully.
The array drops. Highly recoverable in the lab — if not forcibly rebuilt.
Why RAID 5 arrays fail
What NOT to do with a failed RAID 5
Is a failed RAID 5 recoverable?
Usually yes — even RAID 5 with two failed disks is highly recoverable, provided it hasn't been forcibly rebuilt. We image every member disk (repairing failed drives in the cleanroom), determine the RAID parameters — stripe size, disk order, parity rotation — and virtually reconstruct the array without the original controller, then extract your data. See the full service: RAID data recovery.
How much does RAID 5 recovery cost?
Simple arrays can start from around $400; indicatively $1,000–$2,200 (SGD) for logical reconstruction, or $1,800–$3,500 when member disks need cleanroom repair. Emergency service is available. Your free diagnosis confirms the exact fixed price. Full detail on our cost guide.