Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751171AbXAUEGN (ORCPT ); Sat, 20 Jan 2007 23:06:13 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751182AbXAUEGN (ORCPT ); Sat, 20 Jan 2007 23:06:13 -0500 Received: from vms040pub.verizon.net ([206.46.252.40]:20638 "EHLO vms040pub.verizon.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751171AbXAUEGM (ORCPT ); Sat, 20 Jan 2007 23:06:12 -0500 Date: Sat, 20 Jan 2007 23:06:07 -0500 From: Gene Heskett Subject: Re: Abysmal disk performance, how to debug? In-reply-to: <45B2E0DD.9020807@seclark.us> To: linux-kernel@vger.kernel.org, Stephen.Clark@seclark.us Cc: Willy Tarreau , Sunil Naidu , Ismail =?utf-8?q?D=C3=B6nmez?= Message-id: <200701202306.09087.gene.heskett@verizon.net> Organization: Not detectable MIME-version: 1.0 Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7bit Content-disposition: inline References: <200701201920.54620.ismail@pardus.org.tr> <20070120200916.GB25307@1wt.eu> <45B2E0DD.9020807@seclark.us> User-Agent: KMail/1.9.5 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2901 Lines: 87 On Saturday 20 January 2007 22:41, Stephen Clark wrote: >Willy Tarreau wrote: >>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 > >Yeah that make a difference: > time dd if=/dev/zero of=/tmp/1GB bs=1M count=1024 | sync >1024+0 records in >1024+0 records out >1073741824 bytes (1.1 GB) copied, 8.86719 seconds, 121 MB/s > >real 0m43.601s >user 0m0.004s >sys 0m3.912s I'd reconsider my new years resolutions for figures like that: #> time dd if=/dev/zero of=/tmp/1GB bs=1M count=1024 | sync 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 24.1455 seconds, 44.5 MB/s real 0m25.218s user 0m0.009s sys 0m5.763s but then I also have only a gig of ram. So does this look normal? -- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Yahoo.com and AOL/TW attorneys please note, additions to the above message by Gene Heskett are: Copyright 2007 by Maurice Eugene Heskett, all rights reserved. - 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/