disk utility 7 pass erase

Should be for all 7, but completely unnecessary. A one pass zero is completely adequate unless your drive falls into the hands of the NSA or someone with very special skills, an electron microscope and an extremely important need to know what's left on your drive. I'm not certain the data is retrievable even then. You can stop it and do the one pass. Select the drive, go to Erase>Security Options.

I understand your concern, but just for anyone else reading this thread:

+*Secure deletion: a single overwrite will do it*+

+The myth that to delete data really securely from a hard disk you have to overwrite it many times, using different patterns, has persisted for decades, despite the fact that even firms specialising in data recovery, openly admit that if a hard disk is overwritten with zeros just once, all of its data is irretrievably lost.+

+Craig Wright, a forensics expert, claims to have put this legend finally to rest. He and his colleagues ran a scientific study to take a close look at hard disks of various makes and different ages, overwriting their data under controlled conditions and then examining the magnetic surfaces with a magnetic-force microscope. They presented their paper at ICISS 2008 and it has been published by Springer AG in its Lecture Notes in Computer Science series (Craig Wright, Dave Kleiman, Shyaam Sundhar R. S.: Overwriting Hard Drive Data: The Great Wiping Controversy).+

+They concluded that, after a single overwrite of the data on a drive, whether it be an old 1-gigabyte disk or a current model (at the time of the study), the likelihood of still being able to reconstruct anything is practically zero. Well, OK, not quite: a single bit whose precise location is known can in fact be correctly reconstructed with 56 per cent probability (in one of the quoted examples). To recover a byte, however, correct head positioning would have to be precisely repeated eight times, and the probability of that is only 0.97 per cent. Recovering anything beyond a single byte is even less likely.+

+Nevertheless, that doesn't stop the vendors of data-wiping programs offering software that overwrites data up to 35 times, based on decades-old security standards that were developed for diskettes. Although this may give a data wiper the psychological satisfaction of having done a thorough job, it's a pure waste of time.+

http://www.h-online.com/newsticker/news/item/Secure-deletion-a-single-overwrite- will-do-it-739699.html

I was saying Security Options>Zero out Data (writes zeros one pass.) Don't know what "1 pass over write" means. I thought you chose 7-Pass Erase. Anyway, if it told you one of the seven was finished -- and I don't know how this would appear, since I've never used the seven pass -- then it has effectively overwritten with one pass. (I believe the seven pass writes random zeros and ones, not just ones.) Just to be on the safe side, you might want to run a one pass now, i.e. Zero out Data. No one is ever going to see that data.

Message was edited by: WZZZ

I think you should be OK with 2 out of the 7 passes. But, as I said, since the 7 pass, unlike the one pass, writes random zeros and ones, you might, just to be on the safe side, run a one pass zero. I don't know enough about this to say with complete certainty that 2 passes of random zeros and ones will safely erase the drive. Perhaps, _and this is a total guess_, two passes of the 7 the way the 7 writes may not adequately erase the drive. I suppose, though this would be an accident that must be statistically extremely unlikely, it's possible writing randomly only twice might leave a small chunk of the drive still recoverable.

Its not a database, the overwrite does not rollback.

No idea what this means.