Data Recovery Case File · NAS & Network Storage · True, and Not What It Sounds Like

You Cannot Read Them — Which Is Not the Same as Nobody Can

His enquiry repeats something he has been told that sounds like a verdict and is really a warning. A four-bay unit with three 2TB disks in an array: "following a power outage it seems to have stopped working. I am told I cannot load the discs into another machine, so I don't know what else to do. The data is mostly music and photos — not actually valuable, but a pain to replace." Whoever told him that was giving good advice badly. He genuinely cannot put those disks in a computer and read them — and that is a caution about what he should not attempt, not a statement about what is possible.

The decode: what the advice meant, and why it matters

Why he cannot read them himself, and this part is entirely correct: disks from a network unit are not formatted the way a desktop drive is. They carry a filesystem belonging to the appliance's own operating system, which desktop systems do not understand. They are also array members rather than independent disks, so each holds fragments of files interleaved with the others according to a layout described in metadata — not whole files sitting in folders.

Why that advice needed the second half: the danger is what happens when you try. Connect one of those disks to a Windows machine and the system, finding a filesystem it cannot parse, will offer to initialise the disk so it becomes usable. That prompt appears helpful, it is worded as the way to make the drive work, and accepting it writes a fresh partition structure over the start of the disk — which is precisely where the array metadata lives. One click, on one member, can turn a recoverable array into a much harder problem. That is what the warning was protecting him from, and it deserved explaining rather than leaving as a flat "you can't."

What is actually possible: the disks are read on equipment that does not need to understand their filesystem at all — imaging works at sector level, below any filing structure. Each member is captured individually, the array parameters are read from the metadata each disk carries, and the volume is assembled offline from the images, where the appliance's filesystem is interpreted with the right tools and nothing can attempt to initialise or rebuild anything. That the original unit is dead is irrelevant to all of it.

Why a power outage did this: the commonest cause of a network unit failing outright. The cut itself is a hard stop with whatever was being written left unfinished; the restoration is a surge into aged power circuitry; and the restart demands every disk spin up at once from cold. Any of the three can end a unit that had been running for years.

On the value question, honestly: he describes the contents as a pain to replace rather than irreplaceable, which is a reasonable basis for deciding. The right order is to get the position and a fixed figure at no cost, then weigh it — and declining afterwards is a perfectly normal outcome.

What to do meanwhile: power the unit down, leave the disks in their bays or label them by bay if removing them, and connect none of them to a computer.

On the bench

Supply and appliance electronics were eliminated separately, since a unit that has lost its power supply to a surge is not a recovery. Members were removed, labelled by bay and imaged individually write-blocked on the Atola TaskForce 2 — imaging operates at sector level and needs no understanding of the appliance's filesystem, which is why disks a desktop cannot read are captured without difficulty. Array parameters were read from member metadata, the volume assembled offline from the images, and no initialisation was permitted at any point.

The outcome

The electronics eliminated first, every member imaged individually and the volume assembled offline from the copies. Free assessment, one fixed written figure including VAT; where a drive has to be opened, 50% of parts and labour is payable upfront with the balance only on success — otherwise no recovery, no fee. The decode, for anyone told their network disks cannot be read: that is true of you and not of the work. Those disks carry the appliance's own filesystem and hold interleaved fragments rather than whole files, so a desktop cannot read them — and worse, Windows will offer to initialise one, which writes over exactly where the array metadata lives. Imaging works below the filesystem entirely, so the disks are captured and the volume assembled offline.

Our case files are drawn from genuine enquiries received by our laboratory over the past ten years, anonymised to protect client confidentiality. Each one describes the diagnostic and recovery procedure our engineers apply to that fault, using the equipment listed.