<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:12pt"><div><br><span></span></div><div style="color: rgb(0, 0, 0); font-size: 16px; font-family: times new roman,new york,times,serif; background-color: transparent; font-style: normal;"><span>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. </span></div><div> </div><div>------------------------<br>Keith Smith</div><div><br></div> <div style="font-family: times new roman, new york, times, serif; font-size: 12pt;"> <div style="font-family: times new roman, new york, times, serif; font-size: 12pt;"> <div dir="ltr"> <hr size="1"> <font face="Arial" size="2"> <b><span style="font-weight:bold;">From:</span></b> Stephen <cryptworks@gmail.com><br> <b><span style="font-weight: bold;">To:</span></b> keith
smith <klsmith2020@yahoo.com> <br> <b><span style="font-weight: bold;">Sent:</span></b> Sunday, August 18, 2013 9:03 PM<br> <b><span style="font-weight: bold;">Subject:</span></b> Re: shred vs writing zeros to wipe a drive<br> </font> </div> <div class="y_msg_container"><br><div id="yiv6863510338"><div dir="ltr">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. </div>
<div dir="ltr">I would say that if you are running a 3 pass shred another pass of 0s is not needed. </div>
<div dir="ltr">Also note I think the dod has a 7pass standard (my recollection on this is possibly out of date or just fuzzy).</div>
<div class="yiv6863510338gmail_quote">On Aug 18, 2013 8:19 PM, "keith smith" <<a rel="nofollow" ymailto="mailto:klsmith2020@yahoo.com" target="_blank" href="mailto:klsmith2020@yahoo.com">klsmith2020@yahoo.com</a>> wrote:<br><blockquote class="yiv6863510338gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div><div style="font-size:12pt;font-family:times new roman, new york, times, serif;"><br><span></span><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman, new york, times, serif;">
<span>Hi All,</span></div><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman, new york, times, serif;"><br><span></span></div><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman, new york, times, serif;">
<span>I have an old computer that I am giving to a friend so I wanted to wipe the drives in preparation for that.</span></div><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman, new york, times, serif;">
<span><br></span></div><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman, new york, times, serif;"><span>The master is 250GB</span></div><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman, new york, times, serif;">
<span>The slave is 1TB.</span></div><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman, new york, times, serif;"><br><span></span></div><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman, new york, times, serif;">
<span>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.</span></div><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman, new york, times, serif;">
<br><span></span></div><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman, new york, times, serif;"><span>The rescue disk I am using is DVD disk one of CentOS 6.3.<br></span></div>
<div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman, new york, times, serif;"><br><span></span></div><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman, new york, times, serif;">
<span>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.</span></div><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman, new york, times, serif;">
<br><span></span></div><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman, new york, times, serif;"><span>Command : shred -zv /dev/sda (this was on the master disk)</span></div>
<div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman, new york, times, serif;"><br><span></span></div><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman, new york, times, serif;">
<span>Then I ran : dd if=/dev/zero of=/dev/sda bs=16M</span></div><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman, new york, times, serif;"><span><br></span></div><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman, new york, times, serif;">
<span>In one of the articles it showed the above command with bs=1M</span></div><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman, new york, times, serif;"><br><span></span></div>
<div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman, new york, times, serif;"><span>Does the size of "bs" matter?</span></div><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman, new york, times, serif;">
<br><span></span></div><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman, new york, times, serif;"><span>Also what about the argument that shred is overkill?</span></div><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman, new york, times, serif;">
<span><br></span></div><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman, new york, times, serif;"><span>Thanks!!</span></div><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman, new york, times, serif;">
<br><span></span></div><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman, new york, times, serif;"><span>Keith<br></span></div><div style="font-style:normal;font-size:16px;background-color:transparent;font-family:times new roman, new york, times, serif;">
<br><span></span></div><div>------------------------<br>Keith Smith</div></div></div><br>---------------------------------------------------<br>
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