From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: [PATCH] scsi_lib.c: continue after MEDIUM_ERROR Date: Fri, 02 Feb 2007 08:53:27 -0600 Message-ID: <1170428007.3380.4.camel@mulgrave.il.steeleye.com> References: <200701301947.08478.liml@rtr.ca> <1170206199.10890.13.camel@mulgrave.il.steeleye.com> <45C2474E.9030306@rtr.ca> <1170366920.3388.62.camel@mulgrave.il.steeleye.com> <45C32C7F.9050706@emc.com> <20070202144211.5a2d2365@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from accolon.hansenpartnership.com ([64.109.89.108]:39686 "EHLO accolon.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161150AbXBBOxe (ORCPT ); Fri, 2 Feb 2007 09:53:34 -0500 In-Reply-To: <20070202144211.5a2d2365@localhost.localdomain> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Alan Cc: Ric Wheeler , Mark Lord , linux-kernel@vger.kernel.org, IDE/ATA development list , linux-scsi On Fri, 2007-02-02 at 14:42 +0000, Alan wrote: > > The interesting point of this question is about the typically pattern of > > IO errors. On a read, it is safe to assume that you will have issues > > with some bounded numbers of adjacent sectors. > > Which in theory you can get by asking the drive for the real sector size > from the ATA7 info. (We ought to dig this out more as its relevant for > partition layout too). > > > I really like the idea of being able to set this kind of policy on a per > > drive instance since what you want here will change depending on what > > your system requirements are, what the system is trying to do (i.e., > > when trying to recover a failing but not dead yet disk, IO errors should > > be as quick as possible and we should choose an IO scheduler that does > > not combine IO's). > > That seems to be arguing for a bounded "live" time including retry run > time for a command. That's also more intuitive for real time work and for > end user setup. "Either work or fail within n seconds" Actually, then I think perhaps we use the allowed retries for this ... So you would fail a single sector and count it against the retries. When you've done this allowed retries times, you fail the rest of the request. James