How can I fix corrupt image on SD card, my os is rasbpian wheezy 7 which got sluggish and I tried to fix it with running fsck ( on my pi and on another 3 linux machines) which did not fix my problems...

2 Answers 2


You can run a live Debian CD on a normal computer + USB SD card reader or a laptop with an SD card slow.

  1. Boot into the live CD.
  2. Plug in the SD card
  3. It should mount
  4. Copy what you need.
  5. Run a low level format ...
    1. For Windows specifically HDD LLF is a really great piece of software
    2. Windows and Macintosh the SD Formatter is also good.
    3. In Linux dd if=/dev/zero of=/dev/???# bs=1M
  6. Low Level format will force the SD card firmware to realign good sectors while discarding of bad.
    1. This might help sort the card out for a short while. But if its a its generic brand, this might only works once or twice and then into the bin because it will get worse, faster.
    2. Look for Genuine SD cards, preferably Class 8 or 10 as they are higher quality.
  7. Reinstall a new image to the NEW SD Card.

Sorry, thats the best you will be able to do. As with corruption, check disk might find it as OK, but in reality the bits are messed up. You would need to track down the binaries or files and replace them but you cannot guarantee if you fixed all the corruption, or if the file will actually be copied properly.

With SD cards, bad sectors are usually managed by the SD firmware, so its not like a traditional drive where you know that sectors xyz is corrupt and file 123 is on it, because SD firmware will try and relocate the sectors dynamically and attempt to fix the data as best it can, even if its corrupted.

  • Why do you think the card is actually corrupt?
    – Bex
    Apr 29, 2014 at 16:26
  • Because you said you tried running fsck on the pi and 3 other machines. You can try and revive it by doing a low level format, sector by sector. But either way, you have to reinstall the image.
    – Piotr Kula
    Apr 29, 2014 at 16:28

If it is sluggish it's probably not due to a corrupt SD-card. Rather, I would guess that you have installed something that uses a lot of resources. Check with top.

  • 1
    I checked everything, no clue what happend, so I bought a new card,the old one useless...
    – zsn
    May 19, 2014 at 13:07

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