Emergency · memory card with capacity mismatch
SD card mounts with an incorrect volume size
Can I recover files when the mounted card size is wrong?
Short answer
Not safely until the physical capacity is confirmed: a partition-table problem, reader limit, counterfeit card or controller fault can each change the reported size. Check the whole device in one known-good reader. If it shows the true capacity, scan read-only; if the size stays wrong, software cannot fill in missing blocks.
The situation
The mounted volume size does not match the printed capacity or prior use.
A wrong capacity means the device is not describing itself correctly, and every scan built on that description inherits the error. The printed size, the size the computer reports and the size the card really has must agree before recovery is worth starting.
01 / Diagnose
Work out what actually disappeared
Four causes look alike. A damaged partition table can describe a volume smaller than the card, an older reader may not handle SDXC capacities, a counterfeit card reports a size its flash does not have, and a failing controller can report nonsense. Each needs a different answer, and only the first is a normal recovery case.
A partition-table issue, reader limitation, counterfeit card, or controller fault can alter the reported geometry.
Check the last known path, trash and backups without writing to the original device.
02 / Protect the source
Preserve the best recovery chance
- 1
Try the card in a second reader and on another computer to rule out a reader that cannot address the full capacity.
- 2
Compare the size of the physical device, not the mounted volume, with the capacity printed on the card.
- 3
If the device size is right and only the volume is short, image the whole device and scan the image for the media formats.
- 4
If the device itself reports a wrong size, stop writing to it entirely and treat it as a hardware case, not a software one.
Do not repartition or reformat the card to restore the correct size, and do not run a capacity test that writes data across the whole card. Both replace what is still readable, and on a counterfeit card the write test destroys the very files that are being looked for.
03 / Choose the method
Match the tool to the source
For stable, readable exFAT, NTFS and FAT16/FAT32 or uncompressed IMG, DD, RAW and BIN images.
Unconfirmed exports are marked .UNVERIFIED.
Software cannot read blocks a controller refuses to deliver, so a counterfeit or failing card is outside its reach and only a lab can address the flash directly. File Recovery Hero reads stably readable exFAT, NTFS and FAT media read-only and cannot infer data that is never returned.
04 / Verify
Check the recovered content, not just its name
Trust the result only when the numbers line up: the image has the size of the physical card, the recovered files have plausible sizes for their format, and each one opens completely. Files that end abruptly at the same offset point to a geometry that is still wrong.
Keep the source until two verified copies exist. One working preview is not enough.
Sources and technical references
FAQ
Questions about this recovery case
Can memory card with capacity mismatch be recovered in this situation?+
A wrong capacity means the device is not describing itself correctly, and every scan built on that description inherits the error. The printed size, the size the computer reports and the size the card really has must agree before recovery is worth starting. The result still depends on what remains readable on the source.
What should I avoid before scanning?+
Do not repartition or reformat the card to restore the correct size, and do not run a capacity test that writes data across the whole card.
Does scanning write to my memory card?+
Your memory card is only read. Nothing is saved to it.
How do I know whether the result is complete?+
Trust the result only when the numbers line up: the image has the size of the physical card, the recovered files have plausible sizes for their format, and each one opens completely.