Both halves of the mirror carried bad sectors — combining the good sectors from each rebuilt a complete image.
A small business ran its server on a two-disk RAID 1 mirror, reasonably assuming the mirror was its backup. The snag was that both disks had quietly been growing bad sectors over the same stretch, and when one finally dropped out the other proved unreadable in places too. With neither disk fully readable on its own, the array failed and no clean copy survived on either side — the very redundancy the mirror was meant to give had been worn away on both halves at once.
We assessed each disk on its own. Both were failing with bad sectors, but — crucially — not in the same places. A mirror means the two disks hold identical data, which works strongly in our favour: a sector unreadable on one disk is very often perfectly readable on the other, so between the pair a complete copy can usually be assembled.
Both members were imaged on DeepSpar Disk Imagers, capturing as much as each could give and logging exactly which sectors each failed on, with the PC3000 for the firmware-level work. We then merged the two images — drawing each good sector from whichever disk could supply it — to rebuild a single, complete image of the volume. Where one disk left a gap, the other almost always filled it, and the combined image came together cleanly.
From the merged image we rebuilt the file system, checked the business's data opened correctly, and returned it all on fresh media.
Between the two ailing disks we reassembled a full, clean copy of the volume and returned all of the business's data, five working days on. The lesson is an important and often-missed one: a mirror guards against a single disk failing suddenly, but when both disks are the same age and degrade together it offers far less protection than it looks to — which is why a RAID still needs a separate backup, and why disks are worth watching for early signs of wear.
DeepSpar DDI · PC3000 — imaging and recovery carried out in-house. Every job is imaged before any recovery work begins, and the original media is 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, controller or failed rebuild. We image every member disk read-only, recover the parameters, then rebuild the array virtually from the copies.
From £500 plus VAT, with no fix, no fee on most jobs and a fixed quote up front; emergency round-the-clock service is available too.
No. A failed rebuild is the single most common cause of permanent loss. Stop, pull the drives labelled with their bay order, and send them to us.
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.