Wiping unused Disk Space "trick"?

Option A. You have 500 gigs of free disk space that you want to completely wipe. You use your wiping program to wipe 500 gigs of unused disk space, which takes hours. (not to mention "wear and tear" on your hard disk....)

Option B. Can you create a large 499 Gig AVI file so this leaves you with only 1 gig of free disk space. You run the wiping program to wipe 1 gig of unused disk space which takes a minute or so. Then you "regular" delete the 499 Gig AVI file.

Does Option B carry the same effectiveness as Option A? Or are you compromising the effectiveness of wiping by trying to take the shortcut?

 

No, you just created a 499 Gig AVI file and put it in the unused space the next time you do a freespace wipe it will still take hours to completely wipe that 499 Gig AVI file. Create 5 partitions at 100 Gigs each it will take less time and you can do one at a time rather than 1 500 Gig partition all in one shot, if you add up the wipe times for 5x100 Gig it will still add to the wipe time for the 500 Gigs. Repartition the drive or do a 500 Gig Freespace wipe.

 

Cett2, using a utility (e.g., R-Wipe&Clean) to wipe the free disk space with a single pass should be at least as fast as the “option B” you describe -- and, possibly a bit faster.

While opinions differ on this subject, many individuals (including myself) believe that a single overwrite is an effective mechanism for file/disk wiping.

 

How long does it take to create a 499 Gig file?

I am under the impression that every program that wipes free space also creates one huge file. So if one was to do a 1 pass zero wipe, speeds should be similar, if not slightly faster.

 

Yes, the wipe utilities with which I am familiar all write a set of large files (e.g., 2GB each) containing the wipe pattern (e.g., random bytes or zeros) to occupy the majority of unused disk space, and then occupy the remainder with one last file. A more technical explanation may be found here.

Wipe utilities that write direct-to-disk, bypassing the file system, may be faster but they are potentially very dangerous to use because of the risk of corruption to a mounted volume.