From owner-freebsd-questions@FreeBSD.ORG Fri Oct 31 15:14:33 2008 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E71451065677 for ; Fri, 31 Oct 2008 15:14:33 +0000 (UTC) (envelope-from jdc@koitsu.dyndns.org) Received: from QMTA01.emeryville.ca.mail.comcast.net (qmta01.emeryville.ca.mail.comcast.net [76.96.30.16]) by mx1.freebsd.org (Postfix) with ESMTP id C9E3B8FC13 for ; Fri, 31 Oct 2008 15:14:33 +0000 (UTC) (envelope-from jdc@koitsu.dyndns.org) Received: from OMTA04.emeryville.ca.mail.comcast.net ([76.96.30.35]) by QMTA01.emeryville.ca.mail.comcast.net with comcast id ZTE51a00L0lTkoCA1TEZwd; Fri, 31 Oct 2008 15:14:33 +0000 Received: from koitsu.dyndns.org ([69.181.141.110]) by OMTA04.emeryville.ca.mail.comcast.net with comcast id ZTD71a01T2P6wsM8QTD9UV; Fri, 31 Oct 2008 15:13:13 +0000 X-Authority-Analysis: v=1.0 c=1 a=QycZ5dHgAAAA:8 a=uwroqaoiwx5mHuhWLi4A:9 a=W01r5jwMvjMamU00V2heDoCMK2kA:4 a=EoioJ0NPDVgA:10 a=LY0hPdMaydYA:10 Received: by icarus.home.lan (Postfix, from userid 1000) id 7336CC9419; Fri, 31 Oct 2008 08:13:07 -0700 (PDT) Date: Fri, 31 Oct 2008 08:13:07 -0700 From: Jeremy Chadwick To: Christoph Kukulies Message-ID: <20081031151307.GA34850@icarus.home.lan> References: <490AC650.3000904@kukulies.org> <20081031110159.GA30244@icarus.home.lan> <490B17D2.6010000@kukulies.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <490B17D2.6010000@kukulies.org> User-Agent: Mutt/1.5.18 (2008-05-17) Cc: Ivan Voras , freebsd-questions@freebsd.org Subject: Re: fastest raw device copy? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 31 Oct 2008 15:14:34 -0000 On Fri, Oct 31, 2008 at 03:36:02PM +0100, Christoph Kukulies wrote: > Ivan Voras schrieb: >> Jeremy Chadwick wrote: >> >>> On Fri, Oct 31, 2008 at 09:48:16AM +0100, Christoph Kukulies wrote: >>> >> >> >>>> What would be the fastest way to do that sector by sector copy? I'm >>>> using dd right now, >>>> >>>> dd if=/dev/ad0 of=/dev/da0 bs=10000000 >>>> >> >> >>> On the flip side, your blocksize (bs) there is quite high for no good >>> reason. I'd pick something more like bs=64k or bs=128k. The default >>> (512) is too small for what you want, but 10MBytes is silly. >>> >> >> Not only that, but "10000000" isn't even correct - it needs to be a >> multiple of sector size. Generally, using suffixes will do the right thing: >> >> dd if=/dev/ad0 of=/dev/da0 bs=1m >> >> > OK, I understand that 10000000 isn't good, I just thought it wouldn't > harm. But if it is a transfer rate killer then I'd better think of > typing ^C now. The command is running for 6 hours now. Six hours? Hmm... That seems too long, but of course the FreeBSD USB stack is involved, and a USB device in general. I would have assumed that copy should have finished after 2-3 hours tops. > An idea how I can check the current amount of transfered byed alongside > the running dd command? Or watch the current i/o rate? iostat or gstat (I'm willing to bet you prefer the latter) will get you what you want, more or less. -- | Jeremy Chadwick jdc at parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |