From owner-freebsd-questions  Sat Feb  9  9: 2: 6 2002
Delivered-To: freebsd-questions@freebsd.org
Received: from sage-american.com (sage-american.com [216.122.141.44])
	by hub.freebsd.org (Postfix) with ESMTP id 82C8037B41B
	for <freebsd-questions@freebsd.org>; Sat,  9 Feb 2002 09:02:02 -0800 (PST)
Received: from SAGEONE (adsl-64-219-30-160.dsl.crchtx.swbell.net [64.219.30.160])
	by sage-american.com (8.9.3/8.9.3) with SMTP id LAA23476
	for <freebsd-questions@freebsd.org>; Sat, 9 Feb 2002 11:01:53 -0600 (CST)
Message-Id: <3.0.5.32.20020209110118.0195ca18@mail.sage-american.com>
X-Sender: jacks@mail.sage-american.com
X-Mailer: QUALCOMM Windows Eudora Pro Version 3.0.5 (32)
Date: Sat, 09 Feb 2002 11:01:18 -0600
To: freebsd-questions@freebsd.org
From: jacks@sage-american.com
Subject: Using dd to clone HD
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Sender: owner-freebsd-questions@FreeBSD.ORG
Precedence: bulk
List-ID: <freebsd-questions.FreeBSD.ORG>
List-Archive: <http://docs.freebsd.org/mail/> (Web Archive)
List-Help: <mailto:majordomo@FreeBSD.ORG?subject=help> (List Instructions)
List-Subscribe: <mailto:majordomo@FreeBSD.ORG?subject=subscribe%20freebsd-questions>
List-Unsubscribe: <mailto:majordomo@FreeBSD.ORG?subject=unsubscribe%20freebsd-questions>
X-Loop: FreeBSD.ORG

On a FBSD box (4.5-stable) with two identical HDs and in the abscence of a
good IDE HD mirror solution in pursuit of making an exact clone of HD0 to
HD1, I thought I would give "dd" a try. I've seen several postings about
the syntax to use and I'm not completely clear about the "bs=0000"
parameter to use, if one is used at all. I seen:

dd bs=4096k if=/dev/ad0 of=/dev/ad1
or...
dd if=/dev/ad0 of=/dev/ad1 bs=8192

or... that the bs should be set to 2048 for "faster" copy.

Questions:
1) Will the above make an exact clone of identical HD0 to HD1..??
2) Should the the "bs" be used..??
3) If "bs" should be use, how do I determine which one: 2048, 4096, 8192...??
4) should bs be used as in #1 or #2 or both okay..??

I suspect this can screw up the HD if not careful.... so any expert tips
appreciated.


Best regards,
Jack L. Stone,
Server Admin

===================================================
Sage-American 
http://www.sage-american.com
jacks@sage-american.com

"My center is giving way, my right is in retreat;
....situation excellent! ....I shall attack!"
===================================================

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-questions" in the body of the message