Data Recovery Case File · Desktop Externals & Aging Drives · He Looked at the Numbers
Reallocation Is a Drive Concealing Its Own Deterioration, and It Works
Her enquiry contains a diagnostic step almost nobody takes. A drive where "the files still show but I can't open any of them anymore. I installed a monitoring tool to see what might be wrong and it's showing an awful lot of bad sectors." That count is a history rather than a symptom. A drive detects failing sectors and quietly relocates their contents, invisibly, for as long as it can — so a large number means this has been happening for a long time.
| Media | 3TB desktop hard drive — directory listings readable while file content is not; self-monitoring reporting extensive sector reallocation |
| Reported situation | Drive in normal service · files listing in the file browser · files not opening · self-monitoring statistics examined by the owner · extensive reallocated sector count reported · contents required |
| Fault class | Progressive surface degradation with reallocation reserve substantially consumed — structures readable while content regions fail; deterioration long-established |
| Equipment used | Self-monitoring statistics read for reallocated and pending counts before any assessment · no further powered use permitted · Atola Insight Forensic error-rate assessment across the surface · imaged write-blocked under strict per-sector timeouts with retries capped · losses mapped per file |
The decode: what those counts record
What a drive does when it finds a failing sector: it moves the contents to a spare sector held in reserve, and remaps the address so that everything continues to work. This happens silently and continuously, and it is designed behaviour rather than a malfunction.
Why that means the count is a history: every reallocation records a sector that failed at some point in the past. A large number is not a snapshot of current condition — it is a tally of a deterioration that has been running for months, entirely invisibly, while the drive appeared to work normally.
Why the visible symptom arrived only now: the reserve of spare sectors is finite. For as long as it lasts, the drive conceals the problem completely — and when it runs low, failures stop being absorbed and start being reported. Files ceasing to open is the point at which concealment stopped working, not the point at which the drive started failing.
What that reframes: the failure is not recent and the discovery is. There was a period of months during which a copy would have succeeded easily, and nothing announced it.
The other figure worth looking at, and it matters more than the first: pending sectors. Those are sectors the drive has detected as failing and has not yet managed to relocate, because it cannot read them to move their contents. Those are the ones currently failing, and a rising count means active deterioration.
Why her symptom fits precisely: directory structures are small, heavily used, and among the most-refreshed regions, so they survive longest. File content occupies the vast majority of the surface and gets read rarely — which is why listings work while opening does not.
Why checking these statistics is worth recommending generally: they are built into every drive, free to read, and constitute the earliest warning available. A rising reallocation count on a drive that still works perfectly is the moment to copy everything off.
What must stop now: powered use. Every access on a drive whose reserve is exhausted is reading across a surface that is failing, and the margin is what a capture needs.
On the bench
Self-monitoring statistics were read for reallocated and pending counts before any assessment — a drive relocating the contents of failing sectors to a finite reserve silently and continuously, so a large reallocated count records months of concealed deterioration rather than current condition, while pending sectors are those detected and not yet relocatable and therefore currently failing. Imaging ran write-blocked under strict per-sector timeouts with retries capped.
The outcome
The monitoring statistics read before any assessment, powered use stopped, and the drive imaged under capped timeouts with losses mapped per file. 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: that count is a history. Your drive has been quietly relocating failing sectors for months, entirely invisibly — and files ceasing to open is the point at which it ran out of reserve, not the point at which it started failing.
Reading a drive's own health statistics
Check them on the drives you still trust — they're built in, free to read, and they're the earliest warning available. A drive relocates the contents of failing sectors to a spare reserve automatically and silently, so a rising reallocated count on a drive that seems perfectly healthy is the moment to copy everything off, months before anything visible happens. Look at pending sectors too: those are ones the drive has detected and cannot yet relocate because it can't read them, which makes them the ones currently failing. And if files list but won't open, that's structures surviving while content regions don't — stop using it.
Stop using it — call Easy Data Recovery on 028 9002 0144; monitoring statistics read before assessment, error rates measured across the surface, imaged under capped timeouts with losses mapped per file.
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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.