From owner-freebsd-questions@FreeBSD.ORG Wed Jun 25 04:33:37 2008 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id C0B7B106567E for ; Wed, 25 Jun 2008 04:33:37 +0000 (UTC) (envelope-from tedm@toybox.placo.com) Received: from mail.freebsd-corp-net-guide.com (mail.freebsd-corp-net-guide.com [65.75.192.90]) by mx1.freebsd.org (Postfix) with ESMTP id 91CC38FC0C for ; Wed, 25 Jun 2008 04:33:37 +0000 (UTC) (envelope-from tedm@toybox.placo.com) Received: from TEDSDSK (nat-rtr.freebsd-corp-net-guide.com [65.75.197.130]) by mail.freebsd-corp-net-guide.com (8.13.8/8.13.8) with SMTP id m5P4XXlZ098802; Tue, 24 Jun 2008 21:33:36 -0700 (PDT) (envelope-from tedm@toybox.placo.com) From: "Ted Mittelstaedt" To: "Wojciech Puchar" , "Steve Bertrand" Date: Tue, 24 Jun 2008 21:34:31 -0700 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.6604 (9.0.2911.0) X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1914 In-Reply-To: <20080623223954.R9580@wojtek.tensor.gdynia.pl> Importance: Normal X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-3.0 (mail.freebsd-corp-net-guide.com [65.75.192.90]); Tue, 24 Jun 2008 21:33:36 -0700 (PDT) Cc: freebsd-questions@freebsd.org, Andrew Falanga Subject: RE: Wipe a drive clean X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 25 Jun 2008 04:33:37 -0000 > -----Original Message----- > From: owner-freebsd-questions@freebsd.org > [mailto:owner-freebsd-questions@freebsd.org]On Behalf Of Wojciech Puchar > Sent: Monday, June 23, 2008 1:40 PM > To: Steve Bertrand > Cc: freebsd-questions@freebsd.org; Andrew Falanga > Subject: Re: Wipe a drive clean > > > >> I'm having no luck finding hits for "wipe drive" or "zero drive" in > >> the mail list archives and I can't believe I'm the first to ask this > >> question but here it is anyway. How can I simply write 0's across a > >> USB thumb drive? I'd rather not install a port, if I can avoid it. I > >> was thinking that something like dd would work, but everything I've > >> tried thus far is not working. What suggestions does everyone have? > > > > Will... > > > > dd if=/dev/zero of=/dev/disk > > > > dd if=/dev/zero of=/dev/disk bs=1m > > bs may be smaller but not the default 512 bytes. it's a block > size. having > very small block will make the process slow > dd if=/dev/random of=/dev/disk bs=1024 The above will wipe the drive clean per the United States Department of Defence Standard 5220.22-M To "sanitize" it per the 5220.22-M stnadard, do the above 3 times. This is intended to destabilise the remnants of data that may exist on the edges of the track of the disk to which the data is written The random device is a lot slower than /dev/zero so the bs isn't as important. Ted