From owner-freebsd-questions@FreeBSD.ORG  Tue May  2 01:21:27 2006
Return-Path: <owner-freebsd-questions@FreeBSD.ORG>
X-Original-To: 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 B9A2416A401
	for <freebsd-questions@freebsd.org>;
	Tue,  2 May 2006 01:21:27 +0000 (UTC)
	(envelope-from stapleton.41@gmail.com)
Received: from xproxy.gmail.com (xproxy.gmail.com [66.249.82.206])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 476EA43D45
	for <freebsd-questions@freebsd.org>;
	Tue,  2 May 2006 01:21:26 +0000 (GMT)
	(envelope-from stapleton.41@gmail.com)
Received: by xproxy.gmail.com with SMTP id s9so1800746wxc
	for <freebsd-questions@freebsd.org>;
	Mon, 01 May 2006 18:21:26 -0700 (PDT)
DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com;
	h=received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references;
	b=eAZOAseXRPcjqc1tMQ3mjRyTYgCsgM5ksHEDXFcxGyqXwIpbYRZCw5aEoqpd6hQ75DX3vgrwsQbDHbHZlevmeOud+sQHCb8ylO0ctDUGHt2nh+tjNET9BNCGqHUe3HQqYLCr2CQK3j9MK1mkgw9TaH7C7lrG24kq8qAl71PRLNc=
Received: by 10.70.74.16 with SMTP id w16mr231518wxa;
	Mon, 01 May 2006 18:21:26 -0700 (PDT)
Received: by 10.70.76.10 with HTTP; Mon, 1 May 2006 18:21:26 -0700 (PDT)
Message-ID: <80f4f2b20605011821v5e6a51c2i458af940512cf42@mail.gmail.com>
Date: Mon, 1 May 2006 21:21:26 -0400
From: "Jim Stapleton" <stapleton.41@gmail.com>
To: freebsd-questions@freebsd.org
In-Reply-To: <80f4f2b20605011820w314d8852t231e65bfebf5f6e6@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: quoted-printable
Content-Disposition: inline
References: <80f4f2b20605011644r87563a0r9141d4a62a28b98b@mail.gmail.com>
	<20060502000409.GZ81777@wantadilla.lemis.com>
	<80f4f2b20605011820w314d8852t231e65bfebf5f6e6@mail.gmail.com>
Subject: Re: dd issues
X-BeenThere: freebsd-questions@freebsd.org
X-Mailman-Version: 2.1.5
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: Tue, 02 May 2006 01:21:27 -0000

On 5/1/06, Greg 'groggy' Lehey <grog@freebsd.org> wrote:
> On Monday,  1 May 2006 at 19:44:00 -0400, Jim Stapleton wrote:
> > I'm trying to back up some of my software, and I'm having some
> > problems, I found something in the archives specifying the need to set
> > a block size of 2k or greater. This makes a backup (I've not tested it
> > yet).
> >
> > My questions are:
> > (1) Why does this work?
>
> Why shouldn't it?

Because the alternative does not work (default block size, block size
less than 2k).

>
> > (2) Is it possible that not using the default/found block size will
> > cause issues?
>
> Yes.
>
> Without more background in what you're trying to do (you don't even
> say what backup program or what medium you're trying to back up to),
> or what your concerns are, it's difficult to answer this question.
> There are no specific issues with block size on most archivers, but in
> general large block sizes (64 kB or larger) will give better
> performance.

program is dd, source medium is CD, destination medium is hard drive.
Possible later medium is compressed files on HD DVD-RW