Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965367AbXATUJt (ORCPT ); Sat, 20 Jan 2007 15:09:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965368AbXATUJs (ORCPT ); Sat, 20 Jan 2007 15:09:48 -0500 Received: from 1wt.eu ([62.212.114.60]:2088 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965367AbXATUJr (ORCPT ); Sat, 20 Jan 2007 15:09:47 -0500 Date: Sat, 20 Jan 2007 21:09:17 +0100 From: Willy Tarreau To: Stephen Clark Cc: Sunil Naidu , Ismail =?iso-8859-1?Q?D=F6nmez?= , linux-kernel@vger.kernel.org Subject: Re: Abysmal disk performance, how to debug? Message-ID: <20070120200916.GB25307@1wt.eu> References: <200701201920.54620.ismail@pardus.org.tr> <20070120174503.GZ24090@1wt.eu> <200701201952.54714.ismail@pardus.org.tr> <20070120180344.GA23841@1wt.eu> <8355959a0701201144x290362d8ja6cd5bc1408475da@mail.gmail.com> <45B273E4.8040302@seclark.us> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <45B273E4.8040302@seclark.us> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1907 Lines: 64 On Sat, Jan 20, 2007 at 02:56:20PM -0500, Stephen Clark wrote: > Sunil Naidu wrote: > > >On 1/20/07, Willy Tarreau wrote: > > > > > >>It is not expected to increase write performance, but it should help > >>you do something else during that time, or also give more responsiveness > >>to Ctrl-C. It is possible that you have fast and slow RAM, or that your > >>video card uses shared memory which slows down some parts of memory > >>which are not used anymore with those parameters. > >> > >> > > > >I did test some SATA drives, am getting these value for 2.6.20-rc5:- > > > >[sukhoi@Typhoon ~]$ time dd if=/dev/zero of=/tmp/1GB bs=1M count=1024 > >1024+0 records in > >1024+0 records out > >1073741824 bytes (1.1 GB) copied, 21.0962 seconds, 50.9 MB/s > > > >What can you suggest here w.r.t my RAM & disk? > > > > > > > >>Willy > >> > >> > > > >Thanks, > > > >~Akula2 > >- > >To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > >the body of a message to majordomo@vger.kernel.org > >More majordomo info at http://vger.kernel.org/majordomo-info.html > >Please read the FAQ at http://www.tux.org/lkml/ > > > > > > > Hi, > whitebook vbi s96f core 2 duo t5600 2gb hitachi ATA HTS721060G9AT00 > using libata > time dd if=/dev/zero of=/tmp/1GB bs=1M count=1024 > 1024+0 records in > 1024+0 records out > 1073741824 bytes (1.1 GB) copied, 10.0092 seconds, 107 MB/s > > real 0m10.196s > user 0m0.004s > sys 0m3.440s You have too much RAM, it's possible that writes did not complete before the end of your measurement. Try this instead : $ time dd if=/dev/zero of=/tmp/1GB bs=1M count=1024 | sync Willy - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/