When the hard-disk half of a Fusion Drive fails, the whole logical volume breaks. Here's how we put it back together.
A family iMac had stopped booting, and an Apple store hadn't been able to help. The machine used a Fusion Drive, which pairs a small fast SSD with a larger hard disk and presents the two to macOS as a single combined volume. It's a clever arrangement with one catch: because the data is spread across both devices, if either one fails the whole volume breaks — and here the hard-disk half had developed a mechanical fault. The SSD was fine, but on its own it was only ever half the story.
We identified the setup as a Fusion (Core Storage) volume and confirmed that the hard-disk component was failing mechanically while the SSD was healthy. Recovering a Fusion Drive is a two-part job: each physical device has to be recovered in its own right, and then the logical volume tying them together has to be reassembled from both.
We recovered the failing hard disk first, imaging it on a DeepSpar Disk Imager to take a complete, gentle copy of a drive that was struggling, with the PC3000 on hand for its firmware. The healthy SSD imaged straightforwardly. With full images of both devices, we then rebuilt the Fusion (Core Storage) logical volume in software, reassembling the data that had been spread across the pair so the underlying file system could be read as a single whole.
From the rebuilt volume we checked the family's photos, home video and documents — the baby photos they were most anxious about among them — opened correctly, then wrote everything to fresh media.
The full contents of the Fusion Drive came back, returned on fresh media after six working days. The lesson worth drawing out is that a Fusion Drive's convenience comes with a shared fate — two devices acting as one means a single failure can take the lot — so a separate backup matters every bit as much as it does on an ordinary drive.
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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From £300 plus VAT for Macs with a removable drive, and £550 for a Fusion Drive. Where the storage is soldered to the logic board it isn't something we take on. No fix, no fee on most jobs.
Yes — with your account password. FileVault and hardware encryption can only be recovered for the device's owner.
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.