Quick question: With dd (and dcfldd) it's east to write "0" (zeros) out to a drive but how can you write just *1" (ones) out instead? <div class="gmail_quote">On 11 August 2010 12:33, Vince Marsters <<a href="mailto:vince@marsters.co.uk">vince@marsters.co.uk</a>> wrote: <blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"> <div text="#000000" bgcolor="#ffffff"><div class="im"> On Wed, 2010-08-11 at 12:15 +0100, John Matthews wrote: <blockquote type="CITE"> What about hd you are still using, but have deleted stuff on them. Is there any way to bring that back, or even completely delete it? I had a program for windows when i used it, but I cant find anything for linux. </blockquote> </div> For data recovery you can use testdisk (its in the Universe repo for Lucid). As for completely delete it then the only way to be 100% certain is to physically destroy the drive but I have been informed by a KrollOntrack employee (they do commercial data recovery as well as commercial erasing solutions) that 3 overwrites with different data stops them from recovering data from a drive. Also it is important to make sure that when doing secure erases that the bit pattern is different for each wipe (e.g. if you write zeros on the first pass then there should be no zeros in the second). Using one of the Gov approved schemes will usually do this. For most home users a single random wipe will be more than enough as this prevents most people getting at any of the data. Vince </div> -- <a href="mailto:ubuntu-uk@lists.ubuntu.com">ubuntu-uk@lists.ubuntu.com</a> <a href="https://lists.ubuntu.com/mailman/listinfo/ubuntu-uk" target="_blank">https://lists.ubuntu.com/mailman/listinfo/ubuntu-uk</a> <a href="https://wiki.ubuntu.com/UKTeam/" target="_blank">https://wiki.ubuntu.com/UKTeam/</a> </blockquote></div> -- Regards Bill Cumming Twitter: @s0l_uk Skype: s0litaire eMail: <a href="mailto:bill@s0l.co.uk">bill@s0l.co.uk</a>