From owner-freebsd-stable@FreeBSD.ORG  Thu Aug 17 13:35:13 2006
Return-Path: <owner-freebsd-stable@FreeBSD.ORG>
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 4F9F516A4DF
	for <freebsd-stable@freebsd.org>; Thu, 17 Aug 2006 13:35:13 +0000 (UTC)
	(envelope-from fbsd-stable@mawer.org)
Received: from mail27.syd.optusnet.com.au (mail27.syd.optusnet.com.au
	[211.29.133.168])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 740CF43D49
	for <freebsd-stable@freebsd.org>; Thu, 17 Aug 2006 13:35:12 +0000 (GMT)
	(envelope-from fbsd-stable@mawer.org)
Received: from [127.0.0.1] (c220-239-234-69.thorn1.nsw.optusnet.com.au
	[220.239.234.69])
	by mail27.syd.optusnet.com.au (8.12.11/8.12.11) with ESMTP id
	k7HDZ9Li024662
	for <freebsd-stable@freebsd.org>; Thu, 17 Aug 2006 23:35:10 +1000
Message-ID: <44E47092.7050104@mawer.org>
Date: Thu, 17 Aug 2006 03:35:14 -1000
From: Antony Mawer <fbsd-stable@mawer.org>
User-Agent: Thunderbird 1.5.0.5 (Windows/20060719)
MIME-Version: 1.0
To: freebsd-stable@freebsd.org
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Subject: 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 <freebsd-stable.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>, 
	<mailto:freebsd-stable-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-stable>
List-Post: <mailto:freebsd-stable@freebsd.org>
List-Help: <mailto:freebsd-stable-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>,
	<mailto:freebsd-stable-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 17 Aug 2006 13:35:13 -0000

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...

Cheers
Antony