Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S269687AbUICN1m (ORCPT ); Fri, 3 Sep 2004 09:27:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S269692AbUICN1l (ORCPT ); Fri, 3 Sep 2004 09:27:41 -0400 Received: from wasp.net.au ([203.190.192.17]:57240 "EHLO wasp.net.au") by vger.kernel.org with ESMTP id S269687AbUICNXY (ORCPT ); Fri, 3 Sep 2004 09:23:24 -0400 Message-ID: <41387071.4010504@wasp.net.au> Date: Fri, 03 Sep 2004 17:24:01 +0400 From: Brad Campbell User-Agent: Mozilla Thunderbird 0.7+ (X11/20040730) X-Accept-Language: en-us, en MIME-Version: 1.0 To: "J.A. Magallon" CC: Lista Linux-Kernel , Jeff Garzik Subject: Re: md RAID over SATA performance References: <1094169937l.17931l.0l@werewolf.able.es> In-Reply-To: <1094169937l.17931l.0l@werewolf.able.es> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3431 Lines: 82 J.A. Magallon wrote: > Hi all... > > I am buildin an array with a linux box, and I run 2.6.8.1 (not stock, but > the mandrake cooker version). > > Disks are 6 SATA drives, plugged to a couple of Promise FastTrak S150 TX4 > cards. > > Problem is that i get really poor performance. A single drive gives about > 57 Mb/s, and a raid1 with two just gives about 64 Mb/s (measured with > hdparm -tT). With the six drives: > > nada:~/soft/kernel# hdparm -tT /dev/sda > > /dev/sda: > Timing buffer-cache reads: 844 MB in 2.01 seconds = 419.96 MB/sec > Timing buffered disk reads: 174 MB in 3.01 seconds = 57.84 MB/sec > nada:~/soft/kernel# hdparm -tT /dev/md0 > > /dev/md0: > Timing buffer-cache reads: 884 MB in 2.00 seconds = 441.63 MB/sec > Timing buffered disk reads: 310 MB in 3.01 seconds = 103.07 MB/sec > > The real goal is to build a raid5 system, but I just tested with raid1. > Here are some real-world figures for you (Not that they mean anything!) srv:/home/brad# hdparm -t -T /dev/md0 /dev/md0: Timing buffer-cache reads: 1340 MB in 2.00 seconds = 668.76 MB/sec BLKGETSIZE failed: File too large Timing buffered disk reads: 182 MB in 3.02 seconds = 60.31 MB/sec srv:/home/brad# df -h Filesystem Size Used Avail Use% Mounted on /dev/hda1 19G 11G 6.5G 64% / tmpfs 252M 0 252M 0% /dev/shm /dev/hda3 165G 21G 136G 13% /raid0 /dev/md0 2.1T 2.0T 114G 95% /raid /dev/md2 459G 101G 358G 22% /raid2 srv:/home/brad# mdadm --detail /dev/md0 /dev/md0: Version : 00.90.01 Creation Time : Sun May 2 18:02:14 2004 Raid Level : raid5 Array Size : 2206003968 (2103.81 GiB 2258.95 GB) Device Size : 245111552 (233.76 GiB 250.99 GB) Raid Devices : 10 Total Devices : 10 Preferred Minor : 0 Persistence : Superblock is persistent Update Time : Fri Sep 3 16:08:03 2004 State : clean, no-errors Active Devices : 10 Working Devices : 10 Failed Devices : 0 Spare Devices : 0 Layout : left-asymmetric Chunk Size : 128K Number Major Minor RaidDevice State 0 8 1 0 active sync /dev/devfs/scsi/host0/bus0/target0/lun0/part1 1 8 17 1 active sync /dev/devfs/scsi/host1/bus0/target0/lun0/part1 2 8 33 2 active sync /dev/devfs/scsi/host2/bus0/target0/lun0/part1 3 8 49 3 active sync /dev/devfs/scsi/host3/bus0/target0/lun0/part1 4 8 65 4 active sync /dev/devfs/scsi/host4/bus0/target0/lun0/part1 5 8 81 5 active sync /dev/devfs/scsi/host5/bus0/target0/lun0/part1 6 8 97 6 active sync /dev/devfs/scsi/host6/bus0/target0/lun0/part1 7 8 113 7 active sync /dev/devfs/scsi/host7/bus0/target0/lun0/part1 8 8 129 8 active sync /dev/sdi1 9 8 145 9 active sync /dev/sdj1 UUID : 05cc3f43:de1ecfa4:83a51293:78015f1e Events : 0.681631 - 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/