NAS disks · bench notes · ADR-2025-3464
Out of the Box, and Still Not Reading.
This one was sent to us by a fellow professional; we did not get it from the person who owned it. He owns an IT company (very small) and this disk came from a customer of his. The images on the disk were pictures of sentimental value. There were no copies of these images made or stored anywhere else. He had already taken all the proper actions: removed the disk from the NAS, connected it to a computer, and tried to read it directly. He said he was unable to read any good sectors
using what he described as his fairly limited
software, so he stopped there. The customer agreed to let us try and recover the data from the disk. 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.
0203 0868633
What failed, and why.
There were two major problems stacked on top of each other. Both types of problem would defeat normal recovery tools. First, you can't successfully read the disk. General-purpose reading tools will issue a read command, wait, and stop if they don’t see anything. They can't reduce the time-out, reset the disk and continue. And they won’t know which head caused the problem. So when attempting to read a disk with failing sectors, normal tools will stop at the first sector that fails and look like they are dealing with a blank disk. Second, the type of information a NAS writes onto its disks is a Linux volume, typically with a manager between the partition table and the file system. Even if you were able to create a complete copy of a working NAS disk, attaching it to a Windows PC will show nothing recognisable. Simply attaching the disk to a PC does not solve either of these problems. NAS work starts at £500 + VAT, and no charge is added for assessments.
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 | Reading through the sectors that had beaten his tools, with the retries limited. | Mapped the heads first, then imaged one face of a platter per pass, with every reset, timeout and the power itself kept under our own control |
| UFS Explorer RAID Recovery | Unpacking the NAS layout from the image → opening the Linux volume underneath it | Recovers the stripe order, then reverse engineers the volume manager the NAS layered above it |
| R-Studio Technician | Rendering every photograph here instead of counting them off in a listing | Constructs an array 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 lab bench, but this time there were measurements taken. Health and read behaviour were profiled first, so the pattern of failing sectors was mapped before beginning the first full pass. This is something no generic tool can accomplish; it can indicate when a read fails, but it does not provide information as to where the problem is located, which head is causing the failure, or if attempting another read will make the problem worse.
Imaging hardware built for sectors that will not answer
All timeouts were set low, resets occurred automatically, and each pass was run by head so that the areas most likely to cause problems (the "difficult" ground) could be avoided until after the easier reads were completed. In fact, most of the disk read fine under these conditions. The areas that had caused failures for his tools were addressed last, once nothing else readable remained behind them.
Read the layers the NAS actually wrote onto the disk
At this point, from the image forward, this was now a matter of layering instead of just sectors: the partition table, then the manager that sat atop it, then the file system in which the shared folders lived. Once worked through in that order, the folders came back in the original configuration and location the owner would recognise, with the photographs in place.
What went home.
The photographs were returned to the sending company on new media, and opened here first. None of the actions taken by the IT staff complicated this process, which is worth saying plainly: he connected the disk to a machine, determined he could not read it, and stopped. Allowing ordinary tools to continue running against failing sectors does not constitute neutrality, and stopping as soon as possible was the part of this project 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.
Published prices are fixed. Memory cards and USB sticks are £250 + VAT. Any stand-alone drive is £300 + VAT. Drive configurations containing multiple disks (RAID, NAS or server) start at £500 + VAT. First assessments are always complimentary. Thereafter, data recovery charges are also fixed in advance and in writing, so you'll always know how much you owe before paying any money. Shut it down, get a quote first (by phone or with the form), then send it in or drop it off at our Guildford intake laboratory, Monday to Friday, 9am to 5:30pm (no appointment needed). On most jobs you only pay if we recover your data.