From owner-freebsd-questions@freebsd.org  Sun Sep 27 11:46:28 2015
Return-Path: <owner-freebsd-questions@freebsd.org>
Delivered-To: freebsd-questions@mailman.ysv.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 by mailman.ysv.freebsd.org (Postfix) with ESMTP id 4613F9D0931
 for <freebsd-questions@mailman.ysv.freebsd.org>;
 Sun, 27 Sep 2015 11:46:28 +0000 (UTC)
 (envelope-from wblock@wonkity.com)
Received: from wonkity.com (wonkity.com [67.158.26.137])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (Client CN "wonkity.com", Issuer "wonkity.com" (not verified))
 by mx1.freebsd.org (Postfix) with ESMTPS id 009DA1AD
 for <freebsd-questions@freebsd.org>; Sun, 27 Sep 2015 11:46:27 +0000 (UTC)
 (envelope-from wblock@wonkity.com)
Received: from wonkity.com (localhost [127.0.0.1])
 by wonkity.com (8.15.2/8.15.2) with ESMTPS id t8RBkGRw042754
 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO);
 Sun, 27 Sep 2015 05:46:16 -0600 (MDT)
 (envelope-from wblock@wonkity.com)
Received: from localhost (wblock@localhost)
 by wonkity.com (8.15.2/8.15.2/Submit) with ESMTP id t8RBkGOK042751;
 Sun, 27 Sep 2015 05:46:16 -0600 (MDT)
 (envelope-from wblock@wonkity.com)
Date: Sun, 27 Sep 2015 05:46:16 -0600 (MDT)
From: Warren Block <wblock@wonkity.com>
To: Polytropon <freebsd@edvax.de>
cc: "William A. Mahaffey III" <wam@hiwaay.net>,
 FreeBSD Questions !!!! <freebsd-questions@freebsd.org>
Subject: Re: dd question
In-Reply-To: <20150927131036.c6b2d9ce.freebsd@edvax.de>
Message-ID: <alpine.BSF.2.20.1509270540450.40168@wonkity.com>
References: <5606A4FF.4090105@hiwaay.net>
 <CA+tpaK3UOEfKSfSjbdcH+R2jaU9=XVBEg++jn5VCbiiUkLF_Tg@mail.gmail.com>
 <56073915.6030707@hiwaay.net> <20150927131036.c6b2d9ce.freebsd@edvax.de>
User-Agent: Alpine 2.20 (BSF 67 2015-01-07)
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII; format=flowed
X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.4.3
 (wonkity.com [127.0.0.1]); Sun, 27 Sep 2015 05:46:16 -0600 (MDT)
X-BeenThere: freebsd-questions@freebsd.org
X-Mailman-Version: 2.1.20
Precedence: list
List-Id: User questions <freebsd-questions.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/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: <https://lists.freebsd.org/mailman/listinfo/freebsd-questions>, 
 <mailto:freebsd-questions-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sun, 27 Sep 2015 11:46:28 -0000

On Sun, 27 Sep 2015, Polytropon wrote:

> On Sat, 26 Sep 2015 19:37:51 -0453.75, William A. Mahaffey III wrote:
>> Update: I tried the dd again w/ 'bs=1m' & it worked much faster:
>
> It's a more "native" block size suited for the devices in question.
> 512 blocks aren't much common anymore.

It's not really about the native block size of the device, but the 
overhead.  Copying 1M with the default blocksize takes 2,048 
transactions.  Setting bs=1M does it in only one.  It works the same 
with spinning disks, although the buffer does not need to be as large. 
Usually 64K or 128K is enough there.

Incidently, the Handbook installation chapter does show the right way to 
install image files.