ufsd NTFS driver on mount: Fixing 'Unknown Error 1000'

I've previously mentioned using the ufsd driver for NTFS or HFS+, because it is significantly faster at writing than the default ntfs-3g driver provided with in Linux, and it supports writing for HFS+ drives even with journaling enabled. (It is available free for non-commercial use).

But what happens if you have a hard power down with an NTFS drive mounted? Or you encounter corruption for whatever reason?

UFSD may give this error upon mounting it for read-write:

mount: Unknown error 1000

This error is because the "dirty" flag is set on the drive and ufsd won't mount it read/write for fear of corrupting it. In many simple cases, you can correct errors in Linux with ntfsfix, from the ntfsprogs package, and also use ntfsfix to clear the dirty flag.

So if the volume in question is /dev/sdb1, I could do the following as root while the drive is unmounted. The first command repairs simple issues. The second clears the dirty flag:

root ~ # ntfsfix /dev/sdb1   
root ~ # ntfsfix -d /dev/sdb1

IMPORTANT NOTE: If you have extremely valuable data, especially that was being written when the failures occurred, you should be very cautious, because these commands may cause you to lose data.

A better approach may be to load Windows and run chkdsk /f  (to fix file system errors) or chkdsk /r (to detect and mark bad sectors) on the offending drive. Chkdsk is much more sophisticated at detecting and fixing errors than anything available in Linux, although it too may cause you to lose data (and some data loss may be inevitable if power goes off while writing). Here is one approach (using a bootable CD) to using chkdsk even if you don't have Windows installed or handy.

Final note, if this drive is not critical for your machine and you mount it from fstab, you can add the errors=remount-ro flag to the fstab mount line, in order to avoid hanging up your boot when things go wrong.