I have started running sudo dosfsck -a in a 512 GB flash drive and it's already been running for almost 2 days. Is this at all normal?

This is happening in a relatively new i5 laptop. I am running Linux Mint 17.1 (rebecca). I could mount the drive and read file before. I decided to run dosfsck because it would mount as read only (while other USB sticks were being mounted read/write).

At this point, I would like to cancel the dosfsck, but I am worried that the USB stick could get corrupted...


This is not normal... it suggests catastrophic failure. 512 MB is tiny so maybe the hardware is dying of old age now?

FAT is pretty crude, I suggest you cut your losses and interrupt the fsck. It's not re-balancing b-trees or something intricate like that. Ctrl+c / kill -SIGINT is the gentlest approach, so it probably won't work. You can escalate to kill -9 (of the corresponding numeric process ID seen in ps) followed by sync...

...to be honest I'm not sure how to see if requests are finished before you remove the drive. You could try the "safely remove"-type options ("stop"?) in GNOME Disks, hidden somewhere behind the cryptic icons. Then unplug the drive and let it cool if it's hot.

If you have any data to recover, "ddrescue" the whole device (/dev/sdb or so, corresponding to the device that appears in dmesg|tail -n 20). You can then mount the output file (mount -oloop DDRESCUE.OUT /mnt). Or copy it and try fsck again (good luck!). Or resort to photorec which recovers most document types from corrupt filesystems, sans filenames.

If you still think the device is worth trusting, you could then try to test it... Reformat the filesystem (e.g. GNOME Disks) and fill it. You can fill a 512 MB filesystem, right? Unmount, replug, test reading all the files back.

  • Hey, thanks a lot for the answer... I feel like an idiot, but it's 512 GB, not MB... sorry
    – jmlorenzi
    Aug 3 '15 at 18:46
  • Finally canceled the dosfsck... booted windows and repaired from there... There seems not to be any damage...
    – jmlorenzi
    Aug 3 '15 at 18:59

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