From owner-freebsd-questions@FreeBSD.ORG Sat Jan 19 23:50:21 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 6425B16A41A for ; Sat, 19 Jan 2008 23:50:21 +0000 (UTC) (envelope-from fbsd06+SJ=dd5dfa55@mlists.homeunix.com) Received: from turtle-out.mxes.net (turtle-out.mxes.net [216.86.168.191]) by mx1.freebsd.org (Postfix) with ESMTP id 3886113C45B for ; Sat, 19 Jan 2008 23:50:21 +0000 (UTC) (envelope-from fbsd06+SJ=dd5dfa55@mlists.homeunix.com) Received: from mxout-04.mxes.net (mxout-04.mxes.net [216.86.168.179]) by turtle-in.mxes.net (Postfix) with ESMTP id 63E5C163F6D for ; Sat, 19 Jan 2008 18:21:08 -0500 (EST) Received: from gumby.homeunix.com. (unknown [87.81.140.128]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.mxes.net (Postfix) with ESMTP id 40C02D059E for ; Sat, 19 Jan 2008 18:21:03 -0500 (EST) Date: Sat, 19 Jan 2008 23:21:00 +0000 From: RW To: freebsd-questions@freebsd.org Message-ID: <20080119232100.7fc1c195@gumby.homeunix.com.> In-Reply-To: <4791A8F3.7090601@highperformance.net> References: <478F0D5A.9090107@highperformance.net> <20080117081414.GB12470@draenor.org> <478F1049.3000706@boosten.org> <20080117083837.GC12470@draenor.org> <20080117094332.K1563@wojtek.tensor.gdynia.pl> <20080117090210.GD12470@draenor.org> <478F8980.1090301@highperformance.net> <20080118175831.72929086@gumby.homeunix.com.> <4791A8F3.7090601@highperformance.net> X-Mailer: Claws Mail 3.0.2 (GTK+ 2.12.5; i386-portbld-freebsd7.0) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: Gutmann Method on Empty Space 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: Sat, 19 Jan 2008 23:50:21 -0000 On Fri, 18 Jan 2008 23:38:27 -0800 "Jason C. Wells" wrote: > It's interesting to note that Gutmann's earlier work said, loosely > "If you do this, you should be fairly certain you data is > unrecoverable." He now says, "A few passes of random data is as good > as can be expected." Those two standards of performance are very > different. But he goes on to say: "Looking at this from the other point of view, with the ever-increasing data density on disk platters and a corresponding reduction in feature size and use of exotic techniques to record data on the medium, it's unlikely that anything can be recovered from any recent drive except perhaps a single level via basic error-cancelling techniques." So even those few passes of random data are overkill. > I just want to make sure that any given day that the police > come take my functioning computers way that nothing can be recovered > that I explicitly deleted. The police just take disk images.