Data Recovery Case File · NAS & Network Storage · No Redundancy by Design
Striping Splits Every File Across Both Drives, So One Missing Member Halves Everything
His enquiry is candid about the arrangement and its consequences. A desktop machine whose power supply failed, holding a two-drive striped array where "both spin up but only one is being recognised" — and he adds, with evident awareness, "I know…" Striping offers no redundancy at all by design: it divides every file across both members in alternating pieces, so a missing drive is not a missing half of the collection but a missing half of every file in it.
| Media | Two-drive striped array from a desktop machine following power supply failure — both members rotating, one not enumerating; no parity or mirroring present |
| Reported situation | Desktop machine power supply failing · two-drive striped array in use · power event suspected to have affected one member · both drives rotating on power · only one member being recognised · drives removed from the machine · supply replaced and a new drive fitted · photographic content sought |
| Fault class | Striped array with one member not enumerating — content distributed in alternating pieces across both; recovery contingent on restoring access to the affected member |
| Equipment used | Striped topology identified as making both members necessary before any expectation was set · both members imaged individually write-blocked · affected member assessed at board level with current draw measured on a controlled bench supply · stripe size and member order derived from content patterns · array assembled offline from the images |
The decode: why one missing drive is worse here than anywhere else
How striping arranges content: in alternating pieces. A file is cut into chunks and those chunks are written to the two drives in turn, so both members hold part of nearly everything.
Why that is done at all: speed and capacity. Two drives read simultaneously deliver roughly twice the throughput, and the arrangement presents as a single larger volume — which is why it is chosen for media work.
What it costs: every redundancy there is. Nothing is duplicated and nothing is calculated, so there is no mechanism to reconstruct a member that is unavailable.
Why one missing member is not half a recovery: the loss is spread evenly. A file split across both drives with one drive absent is missing alternate sections throughout, not its second half.
Why that matters more for some content than others: file size decides it. A file small enough to fit within a single chunk lands entirely on one drive, so small documents and small images survive on whichever member holds them — while large photographs and video do not.
Why the recovery therefore aims at the affected member rather than at the survivor: reading the good drive alone yields fragments. Restoring access to the second drive is the whole of the job, and everything else follows from it.
Why the prospects are reasonable despite that: the drive spins. A member that rotates and fails to enumerate is very often a board or firmware-stage fault rather than a mechanical one, and the power event points that way.
Why the supply failure fits: a failing supply can deliver incorrect or spiking voltage to everything it powers. Boards absorb that and their protective components fail first, which leaves the recording untouched and the drive unable to announce itself.
Why only one member was affected: components differ slightly and one fails before the other. Both drives received the same event and one has so far survived it — which is worth remembering, because the survivor has been stressed too.
What must not happen: no fitting either original drive into the rebuilt machine, and no recreating the array. Both are ways of writing to members that must be read exactly as they stand.
On the bench
The striped topology was identified as making both members necessary before any expectation was set — striping cutting files into chunks written alternately across members for throughput and capacity, with no duplication or parity, so an absent member removes alternate sections throughout each file rather than a contiguous portion. Files smaller than one chunk reside wholly on a single member and survive. Stripe size and member order were derived from content patterns.
The outcome
Striped topology identified before expectations were set, both members imaged individually, and the affected member assessed at board level with draw measured. Free assessment, one fixed written figure including VAT, charged per drive; 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: one missing member is not half your collection but half of nearly every file. Small files that fit in a single chunk survive whole — and the job is restoring access to the second drive.
A striped pair with one drive missing
Don't fit either original drive back into the rebuilt machine and don't recreate the array — both write to members that need reading exactly as they stand. Set expectations correctly: striping cuts every file into chunks written alternately across both drives, so an absent member removes alternate sections throughout each file rather than a contiguous half. Small files that fit inside one chunk survive whole on whichever drive holds them. The prospects rest on the affected member, and a drive that spins but won't enumerate after a supply failure is usually a board fault.
Don't recreate it — call Manchester Data Recovery on 0161 871 0788; topology identified before expectations are set, both members imaged, stripe parameters derived from content patterns.
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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.