From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262470AbVC3Wsp (ORCPT ); Wed, 30 Mar 2005 17:48:45 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262472AbVC3Wsp (ORCPT ); Wed, 30 Mar 2005 17:48:45 -0500 Received: from icecream.egps.com ([38.119.130.6]:25094 "EHLO mail.egps.com") by vger.kernel.org with ESMTP id S262470AbVC3Ws2 (ORCPT ); Wed, 30 Mar 2005 17:48:28 -0500 Date: Wed, 30 Mar 2005 17:48:28 -0500 From: Nachman Yaakov Ziskind To: linux-kernel@vger.kernel.org Subject: Slow SCSI perf in RH 7.3 Message-ID: <20050330174828.B27631@egps.egps.com> Reply-To: awacs@ziskind.us Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.3.23i X-Mailer: Outlook stinks. Dump Outlook. Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org I have a server: 2.4.20-28.7 #1 Thu Dec 18 11:31:59 EST 2003 i686 with SCSI hard disks (not raid): SCSI subsystem driver Revision: 1.00 scsi0 : Adaptec AIC7XXX EISA/VLB/PCI SCSI HBA DRIVER, Rev 6.2.8 aic7899: Ultra160 Wide Channel A, SCSI Id=7, 32/253 SCBs scsi1 : Adaptec AIC7XXX EISA/VLB/PCI SCSI HBA DRIVER, Rev 6.2.8 aic7899: Ultra160 Wide Channel B, SCSI Id=7, 32/253 SCBs blk: queue dfdbe014, I/O limit 4095Mb (mask 0xffffffff) Vendor: FUJITSU Model: MAP3367NP Rev: 5605 Type: Direct-Access ANSI SCSI revision: 03 blk: queue dfdbe214, I/O limit 4095Mb (mask 0xffffffff) Vendor: FUJITSU Model: MAP3367NP Rev: 5605 Type: Direct-Access ANSI SCSI revision: 03 blk: queue dfdbe614, I/O limit 4095Mb (mask 0xffffffff) Vendor: SEAGATE Model: ST373307LW Rev: 0005 Type: Direct-Access ANSI SCSI revision: 03 blk: queue dfdbea14, I/O limit 4095Mb (mask 0xffffffff) scsi0:A:0:0: Tagged Queuing enabled. Depth 32 scsi0:A:1:0: Tagged Queuing enabled. Depth 32 scsi0:A:4:0: Tagged Queuing enabled. Depth 32 Attached scsi disk sda at scsi0, channel 0, id 0, lun 0 Attached scsi disk sdb at scsi0, channel 0, id 1, lun 0 Attached scsi disk sdc at scsi0, channel 0, id 4, lun 0 (scsi0:A:0): 160.000MB/s transfers (80.000MHz DT, offset 127, 16bit) SCSI device sda: 71132959 512-byte hdwr sectors (36420 MB) Partition check: sda: sda1 sda2 sda3 sda4 < sda5 sda6 sda7 sda8 sda9 > (scsi0:A:1): 160.000MB/s transfers (80.000MHz DT, offset 127, 16bit) SCSI device sdb: 71132959 512-byte hdwr sectors (36420 MB) sdb: sdb1 (scsi0:A:4): 160.000MB/s transfers (80.000MHz DT, offset 63, 16bit) SCSI device sdc: 143374744 512-byte hdwr sectors (73408 MB) sdc: sdc1 Journalled Block Device driver loaded used for graphic files server to Apples (via Netatalk 1.5.2-3) with ext3. OS on one disk, data files on the other two. IDE removable storage. It's great with only one user, but with multiple Apple users, it does a passable impression of a boat anchor. Even ssh then comes back one character at a time. Top shows nothing out the ordinary, I think. Here's some typical 'sar -b' stuff: 03:20:00 PM tps rtps wtps bread/s bwrtn/s 03:30:00 PM 3.97 1.97 2.00 75.65 37.09 03:40:00 PM 4.41 2.32 2.09 336.19 122.32 03:50:00 PM 2.93 1.87 1.05 326.00 131.52 04:00:00 PM 2.44 1.80 0.65 294.09 27.97 04:10:00 PM 2.16 0.58 1.57 107.37 53.69 04:20:00 PM 0.81 0.16 0.66 32.26 31.38 04:30:00 PM 1.78 0.72 1.06 84.34 94.09 04:40:00 PM 1.28 0.55 0.73 55.81 97.88 04:50:00 PM 0.69 0.21 0.48 3.78 13.29 05:00:01 PM 1.82 0.51 1.32 6.02 51.81 05:10:00 PM 1.22 0.04 1.18 0.72 89.07 05:20:00 PM 2.60 1.13 1.47 63.19 30.13 05:30:00 PM 1.36 0.31 1.05 3.44 46.59 Average: 2.51 1.57 0.94 42.79 32.36 which I wish I knew well enough to interpret. :-( So, I'd like to do *something* to speed things up. The likely suspects are: 1) Tweak the kernel somehow, in the knowledge that I'll probably just make things worse (caching?) 2) Buy RAID (which level do I want? Is SATA raid faster than SCSI non-raid?) 3) Buy nicer/more expensive hard disks on the current controller, or, perhaps, a faster non-raid controller. All the connections, terminators, etc. seem happy. I would consider trading a little reliability for a lot of performance. The inevitable omitted information upon request. I was hoping for some suggestions from some very kind list members. Thanks! -- _________________________________________ Nachman Yaakov Ziskind, FSPA, LLM awacs@ziskind.us Attorney and Counselor-at-Law http://ziskind.us Economic Group Pension Services http://egps.com Actuaries and Employee Benefit Consultants