On Fri, 15 Nov 2002, Brian wrote: > > 2. create a large file(2MB+ size determined by memory and disk > > geometry?) with a null characters repeated as contents for the file. > > dd if=/dev/zero of=/dev/hda seems to be fairly effective. Usually one > pass with 0s makes the drive immune to software recovery. not quite true, a simple zero-fill does nothing to insure your security, basic tools may not be able to recover the data, but ghost data can be recovered after 5 zero-fills or in that neighborhood. it has to do with the fact that the magnetic media keeps state for a long ass time. and a zero-fill will overwrite "sectors" and "cylinders" but does not visit every single bit on disk. if you want to be sure, dd if=/dev/random of=/dev/<drive> and repeat 10 or so times.... > What I'd like to do is to run wipe on a disk and send it to Ontrack to see > if they can recover it. Unfortunately there's a huge cost to that, but > then I'd know for sure that 35 passes of random bits is truly good enough. > > -Brian if you are going to do 35passes on a 160GB drive, might as well buy a new one because by the time it is done TBmicrodrives will be in the penny range... Munir Nassar RedConcepts.NET