From owner-freebsd-stable@FreeBSD.ORG Mon Aug 21 21:54:34 2006 Return-Path: X-Original-To: freebsd-stable@freebsd.org Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id B753B16A4DE for ; Mon, 21 Aug 2006 21:54:34 +0000 (UTC) (envelope-from frode@nordahl.net) Received: from smtp1.powertech.no (smtp1.powertech.no [195.159.0.145]) by mx1.FreeBSD.org (Postfix) with ESMTP id 303DA43D62 for ; Mon, 21 Aug 2006 21:54:33 +0000 (GMT) (envelope-from frode@nordahl.net) Received: from [192.168.123.190] (s1013-0074.dsl.start.no [195.159.196.170]) by smtp1.powertech.no (Postfix) with ESMTP id EB9EC80BD; Mon, 21 Aug 2006 23:54:31 +0200 (CEST) In-Reply-To: <44E47092.7050104@mawer.org> References: <44E47092.7050104@mawer.org> Mime-Version: 1.0 (Apple Message framework v752.2) Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Message-Id: <92C9E79E-666E-459D-B42B-3509DA7E2440@nordahl.net> Content-Transfer-Encoding: 7bit From: Frode Nordahl Date: Mon, 21 Aug 2006 23:54:22 +0200 To: Antony Mawer X-Mailer: Apple Mail (2.752.2) Cc: freebsd-stable@freebsd.org Subject: Re: The need for initialising disks before use? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 21 Aug 2006 21:54:34 -0000 On 17. aug. 2006, at 15.35, Antony Mawer wrote: > Hi list, > > A quick question - is it recommended to initialise disks before > using them to allow the disks to map out any "bad spots" early on? > I've seen some "uninitialised" disks (ie. new disks, thrown into a > machine, newfs'd) start to show read errors within a few months of > deployment, which I thought one or two might seem okay, but on a > number of machines is more than a coincidence... > > Is it recommended/required to do something like: > > dd if=/dev/zero of=/dev/ad0 bs=1m > > before use to ensure the drive's sector remappings are all in > place, before then doing a newfs? > > FWIW, I've been seeing this on more 6.0 systems that I would have > thought to be just chance... I think the change is that more systems use cheaper SATA drives now. On several occations I have been unable to build a RAID (hardware or software based) on brand new disks due to one of the drives "failing" during initialization. After zeroing all the drives with dd, everything works fine. I'm not sure if vendors cut corners on initially formatting their drives to save some $$ or if SATA just lacks some features over SCSI that causes trouble like this. -- Frode Nordahl