Data Recovery Case File · Portable Drives · Three Layers, Not One
The Clone Was the Loss and the Tidying Up Was the Second One
His enquiry describes a sequence in which every step after the first made things harder. "I cloned my laptop drive onto this 4TB external drive and it wiped the data. The cloning created 3 partitions, which I then had to format and merge to return" the drive to a single volume. Cloning replaces a destination rather than adding to it — and the reasonable work of putting the drive back in order wrote across whatever the clone had left.
| Media | 4TB external hard drive used as a clone destination — original contents replaced by a cloned partition layout, subsequently formatted and merged into a single volume |
| Reported situation | Laptop drive cloned onto an external drive holding existing content · existing content replaced by the clone · clone producing multiple partitions · partitions formatted by the owner · partitions merged into a single volume · original external content required |
| Fault class | Sequential overwrite in three stages — clone replacing the layout, formatting writing fresh structures, merging rewriting the partition table; surviving content bounded by written extent |
| Equipment used | Each stage assessed separately for written extent · total written extent measured against capacity · imaged write-blocked before any reconstruction · original filesystem structures sought beyond the written regions · files validated by opening |
The decode: three operations and what each one covered
The first — the clone. Cloning writes a complete copy of a source onto a destination, replacing whatever was there. It does not create a folder or add files; it replaces the disk, which is the whole point of the operation and why selecting the wrong destination is so consequential.
Why the partitions appeared: the clone reproduced the source's layout. A laptop drive carries several partitions — a system volume, a recovery area, a boot region — and cloning it produced all of them on the destination, which is why a 4TB drive suddenly presented as three unfamiliar volumes.
Why his response was entirely reasonable: he wanted his large drive back as one volume, so he formatted the partitions and merged them. Anybody would, and nothing about the situation suggested that the space still held anything worth preserving.
What that second stage cost: formatting writes fresh structures into each partition, and merging rewrites the partition table and extends a filesystem across the reclaimed space. Those operations wrote at the start of each region and across the boundaries between them — which is precisely where the original filesystem's structures lived.
Why the total written amount is nevertheless bounded: a clone writes as much as the source held, not as much as the destination can hold. A laptop drive cloned onto a 4TB external covers the first portion and leaves the remainder untouched — and formatting and merging write structures rather than filling space.
So what determines how much survives: how large the source drive was relative to the destination. A small laptop drive onto a large external leaves most of the capacity unwritten, and content beyond the cloned region is physically present.
What that means for his particular content: large files stored later on the drive are the likeliest survivors, because they sat beyond the region the clone reached. Anything at the beginning is the least likely.
What must not happen now: nothing further written, and no further partitioning. Every tidying step has cost something, and the drive is now at its best state until it is imaged.
On the bench
Each stage was assessed separately for written extent — cloning replacing a destination with a complete copy of the source including its partition layout, formatting writing fresh structures at the start of each resulting region, and merging rewriting the partition table and extending a filesystem across the reclaimed space. Total written extent was measured against capacity, a clone covering only as much as the source held. Original filesystem structures were sought beyond the written regions.
The outcome
Each stage assessed for written extent, the total measured against capacity, and original structures sought beyond the written regions. 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: cloning replaces a destination rather than adding to it, which was the loss. Formatting and merging were reasonable tidying and they wrote across exactly where the original structures lived — but a clone only covers as much as the source held.
Cloned onto a drive that already held something
Stop tidying and write nothing further — each remedial step costs more, and the drive is at its best state now. Cloning replaces a destination rather than adding to it, so the original loss happened at that moment. The unfamiliar partitions that appeared afterwards were the source's own layout reproduced, and formatting and merging them back into one volume is what anybody would do — but those operations write structures at the start of each region, which is where the original filesystem's structures were. The encouraging arithmetic is that a clone only covers as much as the source held, so a small drive onto a large one leaves most of the capacity untouched.
Write nothing further — call Easy Data Recovery on 028 9002 0144; each stage assessed for written extent, total measured against capacity, original structures sought beyond the written regions.
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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.