From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030537AbWBNJtT (ORCPT ); Tue, 14 Feb 2006 04:49:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030539AbWBNJtT (ORCPT ); Tue, 14 Feb 2006 04:49:19 -0500 Received: from lucidpixels.com ([66.45.37.187]:48076 "EHLO lucidpixels.com") by vger.kernel.org with ESMTP id S1030537AbWBNJtS (ORCPT ); Tue, 14 Feb 2006 04:49:18 -0500 Date: Tue, 14 Feb 2006 04:49:17 -0500 (EST) From: Justin Piszcz X-X-Sender: jpiszcz@p34 To: Mark Lord cc: Linda Walsh , smartmontools-support@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: Re: default hdparms? readahead=256? Re: WD 400GB xATA Drives In-Reply-To: <43F15027.2090304@rtr.ca> Message-ID: References: <43F1393D.9050801@tlinx.org> <43F15027.2090304@rtr.ca> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Turned out I had too many devices in the box, I have removed them now, still getting those pesky drive errors though, I will try the hdparm soon, thanks. On Mon, 13 Feb 2006, Mark Lord wrote: > 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. >