How do you repair an "input/output error" in an NTFS partition?

ntfsfix worked for me :

sudo ntfsfix /dev/sdb1

Provided in the ntfs-3g package.

chkdsk /R is a pretty important command when things get hairy with NTFS. Unfortunately I don't know of a Linux tool that comes close to covering everything it does. In short, to run it, you're going to need some sort of Windows recovery disk.

If you don't have one to hand, there's an ISO offered up in a thread on another set of support forums (see the first answer).

There are tools like ntfsfix (part of the ntfsprogs package) that can do surface checks on NTFS disks but they don't tend to be able to fix the drives.

NTFS is a closed source Microsoft file system, and you'll need Windows to repair it, by running chkdsk /f, as suggested. If the problem is hardware related, you'll have to replace the hdd.