Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261566AbVEAJA4 (ORCPT ); Sun, 1 May 2005 05:00:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261567AbVEAJA4 (ORCPT ); Sun, 1 May 2005 05:00:56 -0400 Received: from pfepc.post.tele.dk ([195.41.46.237]:27702 "EHLO pfepc.post.tele.dk") by vger.kernel.org with ESMTP id S261566AbVEAJAt (ORCPT ); Sun, 1 May 2005 05:00:49 -0400 Message-ID: <42749AF2.3010107@danbbs.dk> Date: Sun, 01 May 2005 11:01:38 +0200 From: Mogens Valentin Reply-To: monz@danbbs.dk Organization: Mr Dev User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030624 Netscape/7.1 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Alan Cox CC: Bryan Henderson , Anton Altaparmakov , aia21@hermes.cam.ac.uk, Linux Kernel Mailing List , linux-scsi@vger.kernel.org, mike.miller@hp.com Subject: Re: [Question] Does the kernel ignore errors writng to disk? References: <1114812035.18330.396.camel@localhost.localdomain> In-Reply-To: <1114812035.18330.396.camel@localhost.localdomain> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1053 Lines: 25 Alan Cox wrote: > The next question is what the I/O device does with the data. SCSI disks > will cache but the scsi layer uses tags and if neccessary turns the > cache off on the drive. In other words you should get that behaviour > correctly on SCSI media. > > The default IDE behaviour doesn't turn write cache off and the IDE > device may re-order writes and ack them before they hit storage. IDE > lacks tags, and tends to have poor performance on cache flush commands. > With the barrier support on the right thing should occur, or with hdparm > used to turn the write cache off. Is this IDE behaviour confined to IDE drives only? SATA, when using libata, will solemnly be part of the SCSI chain, and hense not subject to your mentioned write cache problem, right? -- Kind regards, Mogens Valentin - 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/