Data Recovery Case File · NAS & Network Storage · The Configuration Was Elsewhere
A Striped Set Depends on a Description That Is Not Always on the Drives
His enquiry describes a precaution that created the problem. Drives removed before a clean system installation and reconnected afterwards, where "they did not show in the file browser and said they had failed in volume management." Removing them was intended to keep them safe — and on a striped pair, what matters is where the description of the arrangement was stored, because without it two drives holding alternating pieces are unreadable.
| Media | Two drives configured as a striped set without redundancy — disconnected during a clean system installation and reported as failed on reconnection |
| Reported situation | Clean system installation performed with all drives disconnected · striped pair reconnected afterwards · drives not appearing in the file browser · volume management reporting the set as failed · content required |
| Fault class | Array description lost with member drives intact — striped content requiring correct order and parameters to be interpretable; no redundancy present |
| Equipment used | Array description sought on the members before any rebuild was considered · each member imaged individually write-blocked · stripe order and unit size derived from content patterns within the images · array assembled offline from images and verified against recovered file structures · no initialisation permitted on the original drives |
The decode: what a striped set is, and what was lost when the installation ran
What striping does: divides content across two drives in alternating pieces. A file is split so that consecutive chunks sit on different drives, which makes it faster to read and means neither drive holds anything usable alone.
Why that is the crucial property here: there is no redundancy. Each drive holds half of everything rather than a copy of anything, and reassembling requires knowing which drive comes first and how large each piece is.
Where that description is held, and this is the variable: it depends on how the set was created. Some arrangements write it onto the drives themselves; others hold it in the machine — in its firmware settings or in the operating system's own configuration.
Why a clean installation matters so much in the second case: it replaces the operating system's configuration entirely. An arrangement recorded there is erased by the installation, and reconnecting the drives afterwards presents two members with nothing describing how they relate.
Why the system reports them as failed: it finds drives it cannot interpret. Failed is its description of an array it cannot assemble, not a finding about the hardware — and both drives may be in perfect health.
Why his precaution was sound and incomplete: disconnecting drives during an installation protects them from being written to, which is genuinely the right instinct. What it does not protect is a description held somewhere other than on the drives, and that is invisible until it matters.
Why the situation is recoverable: the members are intact and the description is derivable. Stripe order and piece size leave patterns in the content itself — file structures spanning the boundary reveal where one drive's contribution ends and the other's begins.
How that is established: each drive is imaged individually, and candidate orders and sizes tested against the images until file structures reconstruct correctly. The correct arrangement is the one that produces readable files, which is a verifiable result rather than a guess.
Why nothing is done on the original drives: the array is assembled offline from images. Any attempt to recreate the set in the machine risks writing a new description over content, which on a striped pair is the one action that would cause real loss.
What must not happen: no initialising either drive, no recreating the array, and no accepting any offer to prepare them. The system regards them as failed and will offer to make them usable, which would write over the very content being reassembled.
On the bench
The array description was sought on the members before any rebuild was considered — striping dividing content across drives in alternating pieces so that neither holds anything usable alone and reassembly requires member order and unit size, that description being held either on the drives or in the host's firmware or operating system configuration, the latter being replaced by a clean installation. Stripe order and unit size were derived from content patterns within the images, structures spanning boundaries revealing the arrangement.
The outcome
The array description sought on the members, each imaged individually, and the arrangement derived from content patterns and verified against recovered structures. Free assessment, one fixed written figure including VAT, charged per drive, with 50% of parts and labour upfront and the balance only on successful recovery. The decode: your drives are probably fine. A striped set needs a description of order and piece size, and if that lived in the machine's configuration rather than on the drives, the clean installation took it — which is what failed means here.
A striped array reported as failed after a system reinstall
Refuse any offer to initialise the drives or recreate the array — the system reports them as failed because it can't interpret them, and recreating the set writes a new description over content that on a striped pair is the one thing you can't lose. Disconnecting them during the installation was the right instinct: it protected them from being written to. What it couldn't protect was the description of how they relate, which on some arrangements lives in the machine's configuration rather than on the drives, and a clean install replaces that. The order and piece size can be derived from the content itself.
Don't recreate the array — call Easy Data Recovery on 028 9002 0144; description sought on the members, each imaged individually, arrangement derived from content patterns and verified.
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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.