I've tested this and it's worked fine for me every time (plus there is no real reason why it should go wrong). However I don't know how it'll perform if you've got a harddrive bigger than 1 gig. If you've got a harddrive that's bigger than 1 gig but it's getting more and more full, then it might still work if it doesn't then tough luck.
P.S. This is only a short crap command that I wrote in about 30s so it's not infallible (no moaning).