From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267468AbUHVPna (ORCPT ); Sun, 22 Aug 2004 11:43:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267469AbUHVPna (ORCPT ); Sun, 22 Aug 2004 11:43:30 -0400 Received: from [213.188.213.77] ([213.188.213.77]:6549 "EHLO server1.navynet.it") by vger.kernel.org with ESMTP id S267468AbUHVPnZ (ORCPT ); Sun, 22 Aug 2004 11:43:25 -0400 From: "Massimo Cetra" To: "'Nick Piggin'" Cc: Subject: RE: Production comparison between 2.4.27 and 2.6.8.1 Date: Sun, 22 Aug 2004 17:43:18 +0200 Message-ID: <003f01c4885e$bf688d20$0600640a@guendalin> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.2627 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1441 In-Reply-To: <4127F7FD.5060804@yahoo.com.au> Importance: Normal Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Nick Piggin wrote: > I wouldn't worry too much about hdparm measurements. If you > want to test the streaming throughput of the disk, run dd > if=big-file of=/dev/null or a large write+sync. Created a big file: -rw-r--r-- 1 root root 1073740800 Aug 22 17:22 /testfile time dd if=/testfile of=/dev/null gives: On 2.6.8.1 ext3 raid real 0m11.493s user 0m0.657s sys 0m2.796s On 2.6.8.1 xfs: real 0m18.214s user 0m0.697s sys 0m3.778s Tests on 2.6.8.1 has been done with elevator=deadline On 2.4.7 ext3 raid: real 0m20.513s user 0m0.704s sys 0m2.626s On 2.4.7 xfs: real 0m28.414s user 0m0.686s sys 0m3.320s So it seems that read access to disks is better on 2.6 tree. > Regarding your worse non-RAID XFS database results, try > booting 2.6 with elevator=deadline and test again. This are results obtained with deadline: filippo:~# dmesg |grep deadline Using deadline io scheduler A) [schema] 2b) 2.6.8.1 and xfs real 0m0.551s user 0m0.027s sys 0m0.012s B) [Importing data] 2b) 2.6.8.1 and xfs real 1m1.474s user 0m3.281s sys 0m1.505s It seems performance does not get better. I have tried other tests: With ext2 FS results are: A) 1c) 2.4.7 and ext2 (no raid) real 0m0.625s user 0m0.028s sys 0m0.018s 2c) 2.6.8.1 and ext2 (no raid) real 0m1.667s user 0m0.026s sys 0m0.010s B) 1c) 2.4.7 and ext2 (no raid) real 1m28.542s user 0m3.232s sys 0m1.384s 2c) 2.6.8.1 and ext2 real 1m30.200s user 0m3.304s sys 0m1.461s Still, even with ext2, 2.4.7 performs much better with postgres (and likely other databases). I have no idea nor no clue how to improve this. > If yes, > are you using queueing (TCQ) on your disks? How can i check ? Massimo Cetra