A dual-parity array shrugs off two dead disks; a third took it offline and halted production. We rebuilt it against the clock.
When a third disk failed in a manufacturing firm’s eight-disk RAID 6, the array had finally run out of protection. RAID 6 is built to keep going through two simultaneous disk failures, but a third is one too many: the parity can no longer cover the gap, and the whole array drops offline — which is exactly what happened, bringing the firm’s single most important server, and its production line with it, to a stop. With downtime costing money by the hour, we took it on as an emergency and worked it round the clock rather than through the normal queue.
Every one of the eight disks came onto the bench at once. Several were ailing to different degrees, which is what you tend to find at this point — the disks are usually the same age from the same batch, so they reach the end of their lives together. With three already down on a two-parity array there was no slack left at all, so the priority was to extract as much as physically possible from each weak disk: the more complete every image, the more the parity would have to work with when reconstructing what the failing disks couldn’t hand over.
We cloned each disk on its own, running several at once to buy back time. The struggling drives went onto DeepSpar imagers to wring the last good sectors out of drives that were nearly spent, while the PC3000 handled anything failing at the firmware level. From the finished images we reverse-engineered how the RAID 6 had been laid out — the stripe size, the sequence of the disks, and the way its two parity sets rotated around the array — and reassembled it entirely in software, using the double parity to fill in what the weakest disks couldn’t. Since none of this touched the physical disks, the recovery couldn’t make the situation any worse.
We confirmed the reassembled file system was complete and opened cleanly — the production databases the firm depends on among it — and delivered the lot back on fresh media.
Inside 48 hours of the disks landing with us the entire file system was back and the firm was operating again. It’s a blunt reminder that even a resilient array has a limit: a batch of same-age disks can fail one after another in short order, so a current backup kept off the array — and reacting the moment the first disk goes rather than carrying on — is what turns a potential catastrophe into a mere scare.
DeepSpar DDI · PC3000 — every member disk imaged in parallel and the array rebuilt from the copies, on an expedited round-the-clock basis. The originals are only ever read, never written to.
Send us your device for a free diagnostic, and tell us a little about what happened — an engineer will review it and confirm your exact quote in writing before any work begins.
Getting your data back begins with getting the device to us. Pack it up safely, pop your contact details inside, and send it over — once we’ve run the free diagnostic, we’ll confirm your exact price in writing before any work starts.
Posting it? A tracked, insured service is what we’d recommend. Rather drop it in? You’re welcome Monday to Friday, 9am to 5:30pm — just package the device up as above first.
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Yes — any level, any controller, including a failed rebuild. We copy every member disk read-only, work out the array’s geometry, then reassemble it virtually from the images so the originals are never altered.
From £500 plus VAT, most jobs no fix, no fee, with a fixed quote up front. For situations like a downed production server we also offer an emergency, round-the-clock service.
Not necessarily. Even with multiple failures we can often rebuild an array by imaging every disk as fully as possible and reconstructing from parity. Don’t attempt a rebuild — power it down, label the disks by bay, and send them in.
Start with an instant online quote, or call and talk it through with us first. You'll have a clear, fixed price before any work begins.