From mboxrd@z Thu Jan 1 00:00:00 1970 From: Szakacsits Szabolcs Subject: Re: What happens to pages that failed to be written to disk? Date: Thu, 28 Jul 2005 10:38:20 +0200 (MEST) Message-ID: References: <20050728003326.4add1a0f.akpm@osdl.org> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: Martin Jambor , linux-fsdevel@vger.kernel.org Return-path: Received: from mlf.linux.rulez.org ([192.188.244.13]:17938 "EHLO mlf.linux.rulez.org") by vger.kernel.org with ESMTP id S261382AbVG1Ii0 (ORCPT ); Thu, 28 Jul 2005 04:38:26 -0400 To: Andrew Morton In-Reply-To: <20050728003326.4add1a0f.akpm@osdl.org> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Thu, 28 Jul 2005, Andrew Morton wrote: > Martin Jambor wrote: > > > > Do filesystems try to relocate the data from bad blocks of the > > device? Only Windows NTFS, not others AFAIK (most filesytems can mark them during mkfs, that's all). > Nope. Disks will do that internally. If a disk gets a write I/O error > it's generally dead. That's what I thought also for over a decade (that they are basically dead soon) so originally I disabled NTFS resizing support for such disks (the tool is quite widely used since it's the only free, open source NTFS resizer). However over the last three years users convinced me that it's quite ok having a few bad sectors (not only in the remapping area). I investigated several "dead" disks and the pattern was that they had maximum a dozen bad sectors, the disk quality didn't degrade in time and users sweared they never had any problem (crash, data loss, corruption, whatever). So recently I added optional support for working with such "dead" disks and this is a bit frustrating since if users don't run badblocks in such cases when creating the Linux filesystems then they will have a hopefully not too spectacular encounter with these sectors sooner or later. Of course I don't say that all disks having bad sectors are totally ok and never will die. Only that that it seems some subset of them seems to keep working perfectly fine (the issue looks similar to the "having a few dead pixel" problem on some LCD's and laptops). Szaka