From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265352AbUBPDry (ORCPT ); Sun, 15 Feb 2004 22:47:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265359AbUBPDry (ORCPT ); Sun, 15 Feb 2004 22:47:54 -0500 Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:35481 "EHLO www.linux.org.uk") by vger.kernel.org with ESMTP id S265352AbUBPDrv (ORCPT ); Sun, 15 Feb 2004 22:47:51 -0500 Message-ID: <40303D59.4030605@pobox.com> Date: Sun, 15 Feb 2004 22:47:37 -0500 From: Jeff Garzik User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030703 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Chip Salzenberg CC: Bartlomiej Zolnierkiewicz , Linux Kernel , Andrew Morton Subject: Re: Linux 2.6.3-rc3 - IDE DMA errors on Thinkpad A30 References: <200402151658.57710.bzolnier@elka.pw.edu.pl> <20040215163438.GC3789@perlsupport.com> <200402151808.42611.bzolnier@elka.pw.edu.pl> <20040216005523.GD3789@perlsupport.com> <40302783.6020505@pobox.com> <20040216033740.GE3789@perlsupport.com> In-Reply-To: <20040216033740.GE3789@perlsupport.com> 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 Chip Salzenberg wrote: > Still: I wonder if the occasional bad sector is really that bad. > Shirley, at the unreal densities of today's drives, the development of > bad sectors is inevitable? (Especially in a laptop drive that's > bounced around in normal use.) Open argument :) A lot of smart people will argue that a bad sector every now and again occurs, and "I've run my server's disks that way for years." Other equally smart people argue that modern IDE disks reserve space for remapping bad sectors. If you run out of sectors that the drive is willing to silently remap for you, you should toss the disk and buy a new one. There is of course the caveat that it is impossible to avoid the drive returning "bad sector", instead of silently remapping, on reads. Oh, and I just thought of something else. Current Linux filesystems will, on a read error, usually mark it as a bad sector and move on. Really, they should attempt to write to the bad sector before considering it bad. As a result, current kernels will AFAICT assume a sector is bad even when the drive politely swaps a good sector in place for you. One for the todo list, I suppose... a useable workaround for this is probably good ole 'e2fsck -c', i.e. badblocks... That says "check again to see if this sector is bad", and -hopefully- will unmark bad blocks that were incorrectly marked bad. Jeff