From owner-freebsd-questions@FreeBSD.ORG Wed May 28 07:39:53 2003 Return-Path: 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 2E1F137B401 for ; Wed, 28 May 2003 07:39:53 -0700 (PDT) Received: from mta03-svc.ntlworld.com (mta03-svc.ntlworld.com [62.253.162.43]) by mx1.FreeBSD.org (Postfix) with ESMTP id E3D5743FA3 for ; Wed, 28 May 2003 07:39:49 -0700 (PDT) (envelope-from scott@fishballoon.org) Received: from fishballoon.org ([81.104.195.199]) by mta03-svc.ntlworld.com ESMTP <20030528143949.KKNQ11246.mta03-svc.ntlworld.com@fishballoon.org>; Wed, 28 May 2003 15:39:49 +0100 Received: from tuatara.fishballoon.org (tuatara [192.168.1.6]) by fishballoon.org (8.12.8p1/8.12.8) with ESMTP id h4SEd64o093214; Wed, 28 May 2003 15:39:06 +0100 (BST) (envelope-from scott@tuatara.fishballoon.org) Received: (from scott@localhost) by tuatara.fishballoon.org (8.12.9/8.12.9/Submit) id h4SEd6o7025169; Wed, 28 May 2003 15:39:06 +0100 (BST) (envelope-from scott) Date: Wed, 28 May 2003 15:39:06 +0100 From: Scott Mitchell To: adrian kok Message-ID: <20030528143906.GA25035@tuatara.fishballoon.org> References: <20030528141019.5840.qmail@web21206.mail.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030528141019.5840.qmail@web21206.mail.yahoo.com> User-Agent: Mutt/1.4i X-Operating-System: FreeBSD 4.8-STABLE i386 cc: questions@freebsd.org Subject: Re: advice about copy from disk to disk X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 28 May 2003 14:39:53 -0000 On Wed, May 28, 2003 at 10:10:19PM +0800, adrian kok wrote: > Hi all > > Can you give me advice: quicky copy from disk to disk > > I use command dd and it almost takes the whole day to > copy 80G data! > dd if=seondary master of=secondary slave bs=1024 > (Secondary master to secondary slave)? 1. Use a much larger block size. I think 64k or 128k will be about as good as you can get, but you probably want to experiment to see what works best on your system. 2. Put the drives on separate cables if possible. Most ATA drives are pretty dumb - I imagine your are hogging the bus so that you can't read and write simultaneously. 3. Make sure you have DMA turned on if the drives support it (man atacontrol) and that you're using 80-wire cables if your drives and controller can run at UDMA66 speed or faster. Hope that helps, Scott -- =========================================================================== Scott Mitchell | PGP Key ID | "Eagles may soar, but weasels Cambridge, England | 0x54B171B9 | don't get sucked into jet engines" scott at fishballoon.org | 0xAA775B8B | -- Anon