ntfs-3g wreaked total havoc on my Windows partitions

Binary package hint: ntfs-3g

Ok, this is probably not the best bug report in the world. Still, since the result was massive data loss, I'm going to report it.

I wanted to clear out the unused areas of the two NTFS partitions on my dual-boot Win7/64 and Ubuntu 10.10 beta system. Just to be sure nobody can restore old data with private information in it.

What I did was mount the partitions with ntfs-3g as usual (in fact I always have them mounted in Ubuntu). Then I used

sudo dd if=/dev/zero of=/windows/FILL bs=1G

to fill the unallocated space with a big file of zeros, until disk full error. Then I created files in all the directories to fill THEM up too and overwrite any old entries still in there. Basically I did something like

sudo touch XQQX1000 XQQX1001.... etc

in every directory of the NTFS partition (with a loop of course). Until no more such empty files could be created anywhere (disk full error). I had checked before, there were no files with such names around anywhere so I figured this was save.

Then I used shred -x -u -z (in a loop again) to delete all of this again, first the XQQX.... stuff then the big FILL file. No errors occured, and everything looked normal afterward.

Now, on the next boot of Windows (which was perfectly working before) I got a black screen and nothing else. Rebooting Linux and checking a bunch of directories on the NTFS partition showed nothing unusual - all the XQQX stuff was gone, and I didn't notice any missing files; a couple of files that I tested had the right content. So I booted from the Windows DVD, did a boot repair, which found some problem (that I didn't write down) and announced that it had fixed it, which went very fast. Now on the next boot from the hard disk, Windows started normally at first, then went into CHKDSK, found literally a million or so errors, did a huge bunch of repairs (it took two hours), and left me with two unusable, totally fscked-up NTFS partitions in the end, killing a bunch of fairly important and (blush) not-backed-up data. Further repair attempts, by hand or by automated repair, proved futile.

Obviously I don't have any logs or anything for this. All I can say is that Ubuntu Maverick beta was fully up to date via the Update Manager as of today, September 30, 2010.

If you have an idea how to improve my bug report without endangering yet another partition, please tell me.