NAS disks · bench notes · ADR-2025-3464
Out of the Box, and Still Not Reading.
This one arrived from a fellow professional rather than from the person who owned it. He runs a small IT business, the failed disk belonged to a customer of his, and what was on it were photographs of sentimental value with no second copy anywhere. He had already done the sensible things: the disk out of the NAS, attached to a machine, and read directly. He was unable to read any good sectors
with what he described as his fairly limited
tools, so he stopped there rather than press on with them. The customer had agreed to it coming here. Knowing where your own equipment ends is the whole of that decision.
Same story on yours? Tell us what it does — the look is free.
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What failed, and why.
Two problems sat one on top of the other, and ordinary tools are defeated by both. The first is the reading. A general-purpose tool issues a read, waits, and gives up when nothing answers: it cannot shorten a timeout, cannot reset the disk and carry on, and has no map of which head is at fault. On a disk whose sectors are beginning to fail, that behaviour halts at the first difficulty and looks like a disk with nothing on it. The second is what a NAS writes onto its disks: a Linux volume, usually with a manager between the partition table and the file system, so even a perfect copy of a healthy NAS disk shows a Windows machine nothing it recognises. Attaching it to a PC settles neither question. NAS work opens at £500 + VAT, and the assessment is not charged for.
What the bench did with it.
The order of the job →| Equipment used | Its work on this job | The reason for it |
|---|---|---|
| DeepSpar Disk Imager 4 | Read through the sectors that had defeated his tools, with retries held short | Heads mapped first, then one platter side to a pass, with every reset, every timeout and the power itself kept under our own control |
| UFS Explorer RAID Recovery | The NAS layout unpicked from the image, then the Linux volume underneath it opened | Recovers the stripe order, then unpicks the volume manager the NAS layered above it |
| R-Studio Technician | Every photograph rendered here rather than counted off in a file listing | Puts an array back together from the images, and reads nearly every file system |
What the bench did with it.
Repeat his result, with figures
What he described was reproduced on the bench, this time with numbers against it. Health and read behaviour were profiled first, so the pattern of failing sectors was mapped before any full pass began. That is the part a general tool cannot do: it can report that a read failed, but not where the trouble sits, nor which head is producing it, nor whether the next attempt will make things worse.
Imaging hardware built for sectors that will not answer
Timeouts were kept short, resets automatic, and the pass ordered by head so that difficult ground could be set aside and revisited once the straightforward reading was done. Most of the disk read normally at those settings. The regions that had defeated his tools were gathered last, once nothing readable was still sitting behind them.
Read the layers the NAS actually wrote onto the disk
From the image onward this became a question of layers rather than sectors: the partition table, then the manager above it, then the file system the shares live in. Worked through in that order, the folders came back in the arrangement the owner would recognise, with the photographs where they had been put.
What went home.
The photographs went back the way they came, to the business that sent them on, on fresh media and opened here first. Nothing the IT side did made this harder, which is worth saying plainly: he attached the disk, found he could not read it, and stopped. Ordinary tools left running against failing sectors are not neutral, and stopping early is the part of this job that cost nothing and saved the most.
Begin here if yours is doing the same thing.
Other RAID & NAS work on the log.
Yours doing something similar? Power it down first.
Prices are published and fixed. Memory cards and USB sticks are priced at £250 + VAT. A drive on its own comes to £300 + VAT. Anything holding a second disk, whether RAID, NAS or a server, opens at £500 + VAT. The first look costs nothing, and the figure that follows is fixed and in writing before a penny is charged. Switch it off and post it in. Most jobs carry no fee where no files return.