shred vs writing zeros to wipe a drive

[keith smith]

Thanks for your feedback!  I did the 3+1 because that was the standard config w/o setting a flag to alert that.  Also note this is not my area of expertise.  

 
------------------------
Keith Smith


________________________________
 From: Stephen <cryptworks at gmail.com>
To: keith smith <klsmith2020 at yahoo.com> 
Sent: Sunday, August 18, 2013 9:03 PM
Subject: Re: shred vs writing zeros to wipe a drive
 


It really depends on the data on the drive. How impactful it would be to have that data get into the hands of someone else. And is the 12 hour shred going to equal that. 
I would say that if you are running a 3 pass shred another pass of 0s is not needed. 
Also note I think the dod  has a 7pass standard (my recollection on this is possibly out of date or just fuzzy).
On Aug 18, 2013 8:19 PM, "keith smith" <klsmith2020 at yahoo.com> wrote:


>
>Hi All,
>
>
>I have an old computer that I am giving to a friend so I wanted to wipe the drives in preparation for that.
>
>
>The master is 250GB
>The slave is 1TB.
>
>
>I read a couple articles that suggested using a rescue disk and the shred utility to take care of this.  I also read that shred is not necessary to just write all zero's to the drive.
>
>
>The rescue disk I am using is DVD disk one of CentOS 6.3.
>
>
>
>I ran shred on the fist drive.  It took 4.5 hours to run 3 shred passes plus 1 that writes zeros to the entire drive.
>
>
>Command : shred -zv /dev/sda  (this was on the master disk)
>
>
>Then I ran : dd if=/dev/zero of=/dev/sda bs=16M
>
>
>In one of the articles it showed the above command with bs=1M
>
>
>Does the size of "bs" matter?
>
>
>Also what about the argument that shred is overkill?
>
>
>Thanks!!
>
>
>Keith
>
>
>
>------------------------
>Keith Smith
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