[vox-tech] Most efficient way to wipe hard drives

[Bill Broadley]

Tony Cratz wrote:
> Bill Broadley wrote:
>> Bill Kendrick wrote:
>>> On Thu, Sep 10, 2009 at 04:07:42PM -0700, Bill Broadley wrote:
>>>> Looks like it would be faster to write all zeros then all ones.
>>> "all zeros, then all ones"?  Or "faster to write all zeros _than_ all ones"?
> 
>> Something like 01010101 on the first pass and 10101010 on the second.  Not
>> that it's a big difference.  It's just a paranoid detail.  Overwriting with
>> anything once should do it.  Except for the badblocks.  Secure deletion or
>> destruction is the only way to get those.
> 
> 
> 	Or you can cheat and use 'shred' to do the work for you. After
> 	all that is what the program is for.

Well shred is for files, not disks.  Erasing files is much trickier.  Most
editors make backup copies, undo logs, etc.  Not to mention every time you
edit a file the previous version (typically) gets deleted, thus those blocks
are on the free list and floating around your disk.  Not to mention any blocks
that are swapped out.

I'd consider shred radically less secure than just dd'ing the entire disk,
which is itself less secure than a secure erase.



> 
> 
> 								Tony
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