From owner-freebsd-questions@FreeBSD.ORG  Wed Feb 23 19:05:00 2005
Return-Path: <owner-freebsd-questions@FreeBSD.ORG>
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 E88EA16A4CE
	for <freebsd-questions@freebsd.org>;
	Wed, 23 Feb 2005 19:05:00 +0000 (GMT)
Received: from relay.pair.com (relay00.pair.com [209.68.1.20])
	by mx1.FreeBSD.org (Postfix) with SMTP id 4D3C643D54
	for <freebsd-questions@freebsd.org>;
	Wed, 23 Feb 2005 19:05:00 +0000 (GMT)
	(envelope-from alejandro@varnet.biz)
Received: (qmail 59315 invoked from network); 23 Feb 2005 19:04:59 -0000
Received: from unknown (HELO ale.varnet.bsd) (unknown)
  by unknown with SMTP; 23 Feb 2005 19:04:59 -0000
X-pair-Authenticated: 200.115.214.206
Date: Wed, 23 Feb 2005 16:05:34 -0300
From: Alejandro Pulver <alejandro@varnet.biz>
To: freebsd-questions <freebsd-questions@freebsd.org>
Message-ID: <20050223160534.6d3f3f8d@ale.varnet.bsd>
X-Mailer: Sylpheed-Claws 0.9.12b (GTK+ 1.2.10; i386-portbld-freebsd5.3)
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Subject: Extracting boot sectors
X-BeenThere: freebsd-questions@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: User questions <freebsd-questions.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>,
	<mailto:freebsd-questions-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-questions>
List-Post: <mailto:freebsd-questions@freebsd.org>
List-Help: <mailto:freebsd-questions-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>,
	<mailto:freebsd-questions-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 23 Feb 2005 19:05:01 -0000

Hello,

I would like to know how to extract the MBR to a file, and how to
restore it. Also I would like to know how to do the same with the
partition boot sector and OS loaders.

I think it is as follows (I remember this from somewhere):

dd if=/dev/<disk/partition> of=/<file> bs=512 count=1

But I do not know:
a) Is 512 the correct size for both (MBR and partition boot sectors)?
b) How to extract/restore the OS loader (e.g. for WinNT/2K/XP, that is
NTLDR)?
c) What alternative commands are available for doing this
(extact/restore)?

I would also like to know more about boot sectors and OS loaders. I
would appreciate some links.

Thanks and Best Regards,
Ale