I'm using the FAT32 file system for my pen drive. It frequently has file/data corruptions.

In Windows, I used the scan disk utility to fix the FAT32/NTFS file systems. How can I do this in Ubuntu?

  • 4
    Do you safely eject?
    – nanofarad
    Jun 6, 2012 at 12:20

4 Answers 4


Try typing the following command in the Linux terminal:

sudo dosfsck -w -r -l -a -v -t /dev/sdc1

sdc1 is usually your pen drive. You can find your pen drive by typing mount in terminal. It's somewhere inside. If that command takes too much time for you, avoid -t switch.

  • -w means write to disk immediately.
  • -r means to do disk check interactively (ask you what to do to when encountering errors). On newer versions of dosfsck this is the default.
  • -l means to list the filenames processed.
  • -a means automatically fix errors. Do not use it, if You want to have more control over fixing possible errors.
  • -v means verbose mode. Generates slightly more output.
  • -t means mark unreadable clusters as bad.

If you want to be sure not to lose your data, create a backup of the source device first.

  • What other file system this command capable to fix other than FAT32? Nov 28, 2013 at 8:53
  • @ShaharilAhmad FAT16, which maybe still be used. For example I got an mini 2GB sd card with FAT16.
    – keiki
    Jul 5, 2014 at 9:36
  • But if I don't do -t, then next time it tries again to use the bad clusters next time?
    – keiki
    Jul 5, 2014 at 9:37
  • 1
    "Currently, only 1 or 2 FATs are supported, not 0." Oct 4, 2018 at 15:11
  • don't use -a, but I don't understand how to answer half the questions it asks me!
    – Michael
    Feb 7, 2019 at 4:26

You can try Dosfsck, which is a component of dosfstools.

For this, type in terminal:

sudo apt-get install dosfstools

To use Dosfsck, you have to indicate the device address you want (Ex. /dev/sdb1, /dev/sdb2, or other device.).

To know your device address, open the terminal (CTRL+ALT+T), then run this command:


If your partition is /dev/sdb1, for example, then unmount it first by running this command:

sudo umount /dev/sdb1

Now you can verify and repair your partition by running this command:

sudo dosfsck -t -a -w /dev/sdb1

Hope this helps.


if you receive the following error, when your USB flash drive is not recognized:

Error: Buffer I/O error on device sdb1

Run this command:


If the output is:

end_request: I/O error, dev sdb1, sector 0
Buffer I/O error on device sdb1, logical block 0

Run this command:

sudo dosfsck -t -a /dev/sdb1

Of course, you must change the device address to your needs, like i wrote above.

  • 1
    in 13.04 the umount seems to work also without sudo
    – giuspen
    Jun 7, 2013 at 8:13
  • I've always encountered with the problem that if an external HDD or pen drive was disconnected improperly whilst making operations with it, the permissions would go crazy, making the device virtually useless. Your answer feels like a god-sent to me; thanks a lot man! Jul 22, 2016 at 15:37

dosfsck cheatsheet

These examples will use FAT32 and /dev/sdc1

fsck.vfat -n /dev/sdc1 - a simple non-interactive read-only check

fsck.vfat -a /dev/sdc1 - checks the file system and fixes non-interactively. Least destructive approach is always used.

fsck.vfat -r /dev/sdc1 - interactive repair. User is always prompted when there is more than a single approach to fixing a problem.

fsck.vfat -l -v -a -t /dev/sdc1 - a very verbose way of checking and repairing the filesystem non-interactively. The -t parameter will mark unreadable clusters as bad, thus making them unavailable to newly created files and directories.


Also try:

fsck.vfat -r /dev/sdXn

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