From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030299AbWBNDgN (ORCPT ); Mon, 13 Feb 2006 22:36:13 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030304AbWBNDgN (ORCPT ); Mon, 13 Feb 2006 22:36:13 -0500 Received: from rtr.ca ([64.26.128.89]:3779 "EHLO mail.rtr.ca") by vger.kernel.org with ESMTP id S1030299AbWBNDgM (ORCPT ); Mon, 13 Feb 2006 22:36:12 -0500 Message-ID: <43F15027.2090304@rtr.ca> Date: Mon, 13 Feb 2006 22:36:07 -0500 From: Mark Lord User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.0.1) Gecko/20060130 SeaMonkey/1.0 MIME-Version: 1.0 To: Linda Walsh Cc: Justin Piszcz , smartmontools-support@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: Re: default hdparms? readahead=256? Re: WD 400GB xATA Drives References: <43F1393D.9050801@tlinx.org> In-Reply-To: <43F1393D.9050801@tlinx.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Linda Walsh wrote: >.. > set to known values may not contain "great values". My "readahead" > value seems to boot with a value of "256" for all of my drives. > > Is this not a bit "excessive"? Wow.. that does look a bit HUGE. Thanks for pointing it out, I'm resetting mine back to 128 for now. > Justin Piszcz wrote: >> When I write to this disk for a while, I see this in dmesg (only once >> so far): >> >> [31230.223504] ata6: translated ATA stat/err 0x51/04 to SCSI >> SK/ASC/ASCQ 0xb/00/00 >> [31230.223511] ata6: status=0x51 { DriveReady SeekComplete Error } >> [31230.223515] ata6: error=0x04 { DriveStatusError } >> >> Is there some sort of smart testing going on constantly? I only get >> 26-27MB/s on this 400GB/SATA/16MB/7200RPM drive. I use smartmontools >> to do a daily test. However, even with smart disabled, I get: >> >> # hdparm -t /dev/sde >> /dev/sde: >> Timing buffered disk reads: 78 MB in 3.06 seconds = 25.46 MB/sec >> >> Does anyone know if this drive has problems in Linux or something? >> >> [ 6.895914] Vendor: ATA Model: WDC WD4000KD-00N Rev: 01.0 ... Some drives suck at sequential reads, in favour of doing random seeks very very well. Basically, the on-drive seek algorithm may not favour doing much read-ahead. Try "hdparm -A1" and see if that helps.