From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1423494AbXBPJpg (ORCPT ); Fri, 16 Feb 2007 04:45:36 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1423495AbXBPJpf (ORCPT ); Fri, 16 Feb 2007 04:45:35 -0500 Received: from lazybastard.de ([212.112.238.170]:35684 "EHLO longford.lazybastard.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1423494AbXBPJpf (ORCPT ); Fri, 16 Feb 2007 04:45:35 -0500 Date: Fri, 16 Feb 2007 09:13:21 +0000 From: =?utf-8?B?SsO2cm4=?= Engel To: Juan Piernas Canovas Cc: Jan Engelhardt , sfaibish , kernel list Subject: Re: [ANNOUNCE] DualFS: File System with Meta-data and Data Separation Message-ID: <20070216091321.GA28092@lazybastard.org> References: <20070215200922.GB24643@lazybastard.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 15 February 2007 23:59:14 +0100, Juan Piernas Canovas wrote: > > > Actually, the version of DualFS for Linux 2.4.19 implements a cleaner. In > our case, the cleaner is not really a problem because there is not too > much to clean (the meta-data device only contains meta-data blocks which > are 5-6% of the file system blocks; you do not have to move data blocks). That sounds as if you have not hit the "interesting" cases yet. Fun starts when your device is near-full and you have a write-intensive workload. In your case, that would be metadata-write-intensive. For one, this is where write performance of log-structured filesystems usually goes down the drain. And worse, it is where the cleaner can run into a deadlock. Being good where log-structured filesystems usually are horrible is a challenge. And I'm sure many people are more interested in those performance number than in the ones you shine at. :) Jörn -- Joern's library part 14: http://www.sandpile.org/