RAID 5 is the most common enterprise array – and the most common failure. A RAID 5 survives one drive failure, but the rebuild that follows is where disasters happen: a second drive dies during rebuild, a latent read error surfaces, or the rebuild completes with wrong data and corrupts the whole array.
If your RAID 5 shows degraded status, if a rebuild failed, or if two drives are down – stop. Do not touch the array. Call us.
What happens when a RAID 5 drive fails
The array drops to degraded mode and starts a rebuild from the remaining drives plus parity. If a second drive fails during that window – or has hidden errors – the rebuild fails and the array goes offline. Too many rebuilds are attempted on drives that should have been imaged first, which is why about 30% of the RAID 5 cases reaching our lab were made worse by a failed rebuild attempt.
Why RAID 5 rebuilds fail
- Latent read errors on large (2TB+) drives
- Second drive failure during the rebuild window
- Wrong drive re-inserted into the wrong slot
- Controller defects and cached writes lost on power failure
RAID 5 data recovery vs. rebuild
| Option | What happens | Risk |
|---|---|---|
| Attempt rebuild yourself | Array recalculates parity from all drives | Can corrupt ALL data if a wrong/failed drive is included |
| Professional recovery | Drives imaged first, array rebuilt virtually | Data recovered with minimal risk |
How we recover RAID 5
We image every drive, analyze the stripe and parity layout, and rebuild the array in software – never on your hardware. We identify which drive failed second (and when), exclude bad sectors intelligently, and extract your files. This is exactly the process we used to recover 100% of the data from a 15-disk EqualLogic RAID 5 after two drives failed in one night.
Frequently Asked Questions
Yes – we regularly recover arrays with multiple failed drives, including after a failed rebuild.
Yes. We reconstruct the array virtually, so we don’t need your controller.
Typically 3-15 days depending on array size and complexity; emergency service in 24-48 hours.
No. In 95% of the cases we see, running check disk after a bad rebuild causes more irreversible corruption.
Call 844-223-7243 — engineers answer 24/7 — or start a case online.
No data, no fee