From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mescal.linbit (213-229-1-138.sdsl-line.inode.at [213.229.1.138]) by mail.linbit.com (LINBIT Mail Daemon) with ESMTP id C0FAB14301 for ; Mon, 4 Oct 2004 16:08:44 +0200 (CEST) From: Philipp Reisner To: drbd-dev@lists.linbit.com Subject: Re: [Drbd-dev] How Locking in GFS works... Date: Mon, 4 Oct 2004 16:09:23 +0200 References: <200410041456.21841.philipp.reisner@linbit.com> <200410041526.15189.philipp.reisner@linbit.com> <20041004134912.GY1542@marowsky-bree.de> In-Reply-To: <20041004134912.GY1542@marowsky-bree.de> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8bit Content-Disposition: inline Message-Id: <200410041609.23272.philipp.reisner@linbit.com> List-Id: Coordination of development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Monday 04 October 2004 15:49, Lars Marowsky-Bree wrote: > On 2004-10-04T15:26:15, Philipp Reisner wrote: > > If everything works (esp. the locking of the shared disk fs) no. > > > > But just consider that the locking of the shared disk FS on > > top of us is broken, and that it issues a write request to > > the same block number on both nodes. > > > > Then each node would write its copy first and the peers > > version of the data at second to that block number. > > > > => We would have different data in this block on our > > two copies. - And we would event know about it! > > You would know the moment the replicated write from the remote end came > in, no? > > "Oh my, this is dirty locally too and unacked. We better arbitate now; > ie one side wins and the other one is silently discarded." > This is what I like about mailinglists. This is a new idea, that certainly needs to be considered. Hmm, I just tooks a sheet of paper and drew a view diagrams of it. It works as long as writing the block takes longer than transmitting the block. The scheme simply fails if transmitting takes longer than writing. -Philipp -- : Dipl-Ing Philipp Reisner Tel +43-1-8178292-50 : : LINBIT Information Technologies GmbH Fax +43-1-8178292-82 : : Schönbrunnerstr 244, 1120 Vienna, Austria http://www.linbit.com :