Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261554AbVEPLab (ORCPT ); Mon, 16 May 2005 07:30:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261551AbVEPLaa (ORCPT ); Mon, 16 May 2005 07:30:30 -0400 Received: from krusty.dt.E-Technik.Uni-Dortmund.DE ([129.217.163.1]:31646 "EHLO mail.dt.e-technik.uni-dortmund.de") by vger.kernel.org with ESMTP id S261560AbVEPLaA (ORCPT ); Mon, 16 May 2005 07:30:00 -0400 Date: Mon, 16 May 2005 13:29:56 +0200 From: Matthias Andree To: Arjan van de Ven Cc: Matthias Andree , linux-kernel@vger.kernel.org Subject: Re: Linux does not care for data integrity (was: Disk write cache) Message-ID: <20050516112956.GC13387@merlin.emma.line.org> Mail-Followup-To: Arjan van de Ven , linux-kernel@vger.kernel.org References: <200505151121.36243.gene.heskett@verizon.net> <20050515152956.GA25143@havoc.gtf.org> <20050516.012740.93615022.okuyamak@dd.iij4u.or.jp> <42877C1B.2030008@pobox.com> <20050516110203.GA13387@merlin.emma.line.org> <1116241957.6274.36.camel@laptopd505.fenrus.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1116241957.6274.36.camel@laptopd505.fenrus.org> X-PGP-Key: http://home.pages.de/~mandree/keys/GPGKEY.asc User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1464 Lines: 34 On Mon, 16 May 2005, Arjan van de Ven wrote: > I think you missed the part where disabling the writecache decreases the > mtbf of your disk by like a factor 100 or so. At which point your > dataloss opportunity INCREASES by doing this. Nah, if that were a factor of 100, then it should have been in the OEM manuals, no? Besides that, although my small sample is not representative, I have older drives still alive & kicking - an MTBF of 1/100 of what the vendor stated would mean the chance of failure way above 90 % by now, the drive has seen 22,000 POH with write cache off and has been a system drive for like 14,000 POH. So? > Sure you can waive rethorics around, but the fact is that linux is > improving; there now is write barrier support for ext3 (and I assume > reiserfs) for at least IDE and iirc selected scsi too. See the problem: "I assume", "IIRC selected...". There is no list of corroborated facts which systems work and which don't. I have made several attempts in compiling one, posting public calls for data here, no response. I don't blame you personally, but the lack of documentation about such crucial facts or generally documentation in Linux environments in general. -- Matthias Andree - 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/