From owner-freebsd-questions Sun Aug 25 18:33:28 2002 Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 4511137B400; Sun, 25 Aug 2002 18:33:26 -0700 (PDT) Received: from wantadilla.lemis.com (wantadilla.lemis.com [192.109.197.80]) by mx1.FreeBSD.org (Postfix) with ESMTP id 02AA743E65; Sun, 25 Aug 2002 18:33:25 -0700 (PDT) (envelope-from grog@lemis.com) Received: by wantadilla.lemis.com (Postfix, from userid 1004) id 65AEE812F7; Mon, 26 Aug 2002 11:03:22 +0930 (CST) Date: Mon, 26 Aug 2002 11:03:22 +0930 From: Greg 'groggy' Lehey To: Giorgos Keramidas Cc: Peter Leftwich , FreeBSD LIST Subject: Re: dd if=/dev/zero of=/dev/ad1 Message-ID: <20020826013322.GD88156@wantadilla.lemis.com> References: <20020825005742.W71244-100000@earl-grey.cloud9.net> <20020825050401.GC74424@hades.hell.gr> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20020825050401.GC74424@hades.hell.gr> User-Agent: Mutt/1.3.99i Organization: The FreeBSD Project Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-418-838-708 WWW-Home-Page: http://www.FreeBSD.org/ X-PGP-Fingerprint: 9A1B 8202 BCCE B846 F92F 09AC 22E6 F290 507A 4223 Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Sunday, 25 August 2002 at 8:04:02 +0300, Giorgos Keramidas wrote: > On 2002-08-25 00:59 +0000, Peter Leftwich wrote: >> `dd if=/dev/zero of=/dev/ad1` >> >> Is this the correct command line to totally wipe clean (to all zeroes, e.g. >> factory new) a primary slave HDD? Always learning, > > True. You might want to use a large block size to speed operations if > possible (less I/O calls from dd(1) to the kernel, and more freedom to > the kernel drivers to arrange in which order data is zeroed). Try at > least 32 KB. The optimum is the maximum transfer size, currently 128 kB. Greg -- See complete headers for address and phone numbers To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message