SMART warnings deserves a clear, practical explanation. SMART is the drive reporting on itself, and it is both more useful and less reliable than its reputation suggests. Plenty of drives fail with a clean SMART report. But when SMART does raise certain specific attributes, it is usually right, and the sensible response is to stop using the drive rather than to wait and see.
The short answer. Reallocated sectors, pending sectors and uncorrectable sectors are the three that matter. If any of them is climbing, copy your data off now and do not run a repair tool.
The three that mean stop
- Reallocated Sector Count (05). Sectors that went bad and were swapped for spares. A handful that appeared once and never moved is survivable. A number that grows week to week is a drive shedding surface.
- Current Pending Sector Count (C5). Sectors the drive cannot read and has not yet remapped. This is the most urgent one, because it means there is data sitting in a place the drive can no longer reach.
- Offline Uncorrectable (C6). Sectors that failed verification. Alongside a rising C5, this is a drive in active decline.
The ones people panic about unnecessarily
- Raw Read Error Rate (01). Seagate drives report this in a format that looks terrifying and usually means nothing. Compare against the normalised value, not the raw number.
- Spin Retry Count (0A). A single event from a cold start is not a trend.
- Temperature (C2). Worth fixing, rarely an emergency on its own.
- Power-On Hours. Age is not failure. Plenty of drives run for a decade.
Pending sectors mean copy now, diagnose later
A drive reporting pending sectors is telling you it is on its way out. EaseUS Data Recovery Wizard can image a failing disk sector by sector, giving you one careful pass at hardware that may not cooperate for a second.
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What not to do when SMART is unhappy
Do not run CHKDSK, fsck, or a manufacturer repair utility on a drive with pending sectors. These tools work by forcing reads and writes on the failing areas, which is precisely the stress that turns a marginal sector into a dead one. They are recovery tools for file-system errors, not for hardware.
Do not defragment it either, for the same reason: maximum head movement across a surface that is already struggling.
What to do instead
- Stop normal use of the drive immediately.
- Image it sector by sector to a healthy disk, skipping bad sectors rather than retrying them endlessly.
- Recover your files from the image, not from the failing drive.
- Retire the drive. A drive with a climbing reallocation count does not recover.
Image it before you do anything else
The safest move on a drive with SMART warnings is one pass, one read, copied to somewhere healthy — then work from the copy. Imaging software that handles bad sectors gracefully is what you want here, not a repair tool.