From owner-freebsd-hackers@FreeBSD.ORG Tue Aug 5 19:03:22 2008 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 284881065677 for ; Tue, 5 Aug 2008 19:03:22 +0000 (UTC) (envelope-from ticso@cicely7.cicely.de) Received: from raven.bwct.de (raven.bwct.de [85.159.14.73]) by mx1.freebsd.org (Postfix) with ESMTP id A1EF48FC2C for ; Tue, 5 Aug 2008 19:03:21 +0000 (UTC) (envelope-from ticso@cicely7.cicely.de) Received: from cicely5.cicely.de ([10.1.1.7]) by raven.bwct.de (8.13.4/8.13.4) with ESMTP id m75J3IeX052063 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Tue, 5 Aug 2008 21:03:19 +0200 (CEST) (envelope-from ticso@cicely7.cicely.de) Received: from cicely7.cicely.de (cicely7.cicely.de [10.1.1.9]) by cicely5.cicely.de (8.14.2/8.14.2) with ESMTP id m75J3Cn8001383 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 5 Aug 2008 21:03:12 +0200 (CEST) (envelope-from ticso@cicely7.cicely.de) Received: from cicely7.cicely.de (localhost [127.0.0.1]) by cicely7.cicely.de (8.14.2/8.14.2) with ESMTP id m75J3CxN098932; Tue, 5 Aug 2008 21:03:12 +0200 (CEST) (envelope-from ticso@cicely7.cicely.de) Received: (from ticso@localhost) by cicely7.cicely.de (8.14.2/8.14.2/Submit) id m75J3Bwn098931; Tue, 5 Aug 2008 21:03:11 +0200 (CEST) (envelope-from ticso) Date: Tue, 5 Aug 2008 21:03:11 +0200 From: Bernd Walter To: freebsd-hackers@freebsd.org, Matthias Apitz Message-ID: <20080805190307.GY94193@cicely7.cicely.de> References: <20080805123533.GA3262@rebelion.Sisis.de> <200808051506.m75F69d5039014@lurza.secnetix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200808051506.m75F69d5039014@lurza.secnetix.de> X-Operating-System: FreeBSD cicely7.cicely.de 7.0-STABLE i386 User-Agent: Mutt/1.5.11 X-Spam-Status: No, score=-4.3 required=5.0 tests=ALL_TRUSTED=-1.8, AWL=0.109, BAYES_00=-2.599 autolearn=ham version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on spamd.cicely.de Cc: Subject: Re: restore of file system into USB key terrible slow X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: ticso@cicely.de List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 05 Aug 2008 19:03:22 -0000 On Tue, Aug 05, 2008 at 05:06:09PM +0200, Oliver Fromme wrote: > Matthias Apitz wrote: > > [...] > > > I'm trying to restore a DUMP into an USB key; the DUMP was extracted > > > from another USB key which I just want to colne this way; > > Note that dump/restore isn't a very fast method to clone > a file system. Actually, a few years ago it was horribly > slow, but it was improved somewhat. It's better now, but > still not very fast. Additonally some flash devices are horribly slow when it comes to many small random writes, which writing many small files does. Internally they do read modify writes on physically larger blocks. It is often much faster to do the FS work on an image and then dd the image to the USB stick using 64k to 256k transfers. MLC flash devices are typical candidates for being extremly slow with small random writs. If speed is an issue you should take care and invest in the higher price to buy SLC devices. -- B.Walter http://www.bwct.de Modbus/TCP Ethernet I/O Baugruppen, ARM basierte FreeBSD Rechner uvm.