Reformatting It was running a 15 year old NTFS and it seems to have become (at least partially) corrupted. I decided to do the hardcore thing and reformat all of it. A nifty site1 told me about the mkfs program, which made a lot of sense since I am long-since converted to the values of ext4. I was surprised to learn that my system already had the mkfs program on it, so away we went!