Data Recovery Case File · Cameras, Drones & Cards · A Move Is a Copy and a Delete
A Transfer That Removes the Source Depends Entirely on the Destination Having Worked
This enquiry describes an operation that did half its job. A camcorder holding 38GB on its internal disk, backed up to a memory card, where "it deleted all those files from the internal disk to move them over — however when I checked the card there were no files on it and the internal disk had been wiped." A move is a copy followed by a deletion, and the deletion happened whether or not the copy did.
| Media | Camcorder internal hard drive of approximately 38GB and destination memory card — move operation reported as completed with source cleared and destination empty |
| Reported situation | Camcorder holding approximately 38GB on internal storage · transfer to a memory card initiated as a backup · operation removing content from internal storage · destination card found to contain no files · internal storage reported as cleared · recovery of the footage sought |
| Fault class | Move operation with failed or unwritten destination — source index cleared with content retained; both media requiring assessment as separate targets |
| Equipment used | Both media treated as separate recovery targets rather than one job · camcorder powered down and both media removed before assessment · each imaged write-blocked before any scanning · video located by signature on both and extents rebuilt from stream structure · recovered footage validated by playback in full |
The decode: what a move actually is, and where the footage now sits
What a device means by moving files: two operations in sequence. The content is written to the destination, and then the source entries are removed — and they are separate steps regardless of how the interface presents them.
Why the second can happen when the first has not: the device believes it succeeded. A transfer that reports completion without verifying the destination proceeds to the deletion on trust, and consumer devices verify far less than people assume.
Why the card may genuinely be empty: several possibilities and all ordinary. The card may have been full, write-protected, or unwritable due to a filesystem the camcorder could not use — any of which stops the writing while leaving the deletion to proceed.
Why the internal disk showing empty is the good news: deletion removes entries. Thirty-eight gigabytes of footage does not vanish because an index was cleared, and it remains where it was written.
Why that makes the internal disk the primary target: it held the material for as long as it was recorded. Content written over months sits in long contiguous runs, which is the most recoverable arrangement there is.
Why the card is worth reading too: the transfer may have partly succeeded. Files written before the failure would be present and unreferenced if the index was never completed, so it is a second target rather than a dead end.
What determines how much survives on the internal disk: whether the camcorder has recorded since. A device that believes its storage is empty offers all of it to the next recording, and that is the only thing that would displace the footage.
Why the camcorder must therefore be switched off and left alone: it is the risk. Any further recording writes into exactly the space the footage occupies, and the device has no reason not to.
Why video recovers well from a cleared index: clips carry recognisable openings and are large. They are located by searching the content directly and reassembled from the stream's own structure, without any directory.
What the general practice is, and it is one line: copy, verify, then delete — never move. The verification step is what a move omits, and it is the step that matters.
On the bench
Both media were treated as separate recovery targets rather than one job — a move comprising a write to the destination followed by removal of source entries, executed as separate steps, with consumer devices frequently proceeding to the deletion on trust rather than verifying the destination. A full, protected or incompatibly formatted card halts writing while deletion proceeds. Deletion clears entries while content persists. Video was located by signature on both media with extents rebuilt from stream structure.
The outcome
Both media treated as separate targets, the camcorder powered down and both removed before assessment, and video located by signature on each. Free assessment, one fixed written figure including VAT; on media where content has been deleted, the figure is payable upfront. The decode: a move is a copy and then a delete, and the delete happened on trust. Your footage was never erased — the index describing it was, and the internal disk still holds it.
After a transfer that emptied the source
Switch the device off and leave it off, and take both the internal storage and the card out of use — the device now believes its storage is empty and will offer all of it to the next recording, which is the only thing that would actually destroy your footage. What happened is that a move is a copy followed by a deletion, and consumer devices often proceed to the deletion without verifying the destination wrote successfully. Read the card too, since a partial transfer would leave files there unreferenced. Copy, verify, then delete — never move.
Power the device down — call Cambridge Data Recovery on 01223 655015; both media treated as separate targets, imaged before scanning, video located by signature with extents rebuilt from stream structure.
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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.