Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030671AbXBOTHG (ORCPT ); Thu, 15 Feb 2007 14:07:06 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030675AbXBOTHF (ORCPT ); Thu, 15 Feb 2007 14:07:05 -0500 Received: from mail.um.es ([155.54.212.109]:46830 "EHLO mail.um.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030671AbXBOTHD (ORCPT ); Thu, 15 Feb 2007 14:07:03 -0500 X-Greylist: delayed 1734 seconds by postgrey-1.27 at vger.kernel.org; Thu, 15 Feb 2007 14:07:03 EST Date: Thu, 15 Feb 2007 19:38:14 +0100 (CET) From: Juan Piernas Canovas X-X-Sender: piernas@ditec.inf.um.es To: Jan Engelhardt Cc: sfaibish , kernel list Subject: Re: [ANNOUNCE] DualFS: File System with Meta-data and Data Separation In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: MULTIPART/MIXED; BOUNDARY="916140492-708553444-1171564694=:19998" Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2920 Lines: 78 This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --916140492-708553444-1171564694=:19998 Content-Type: TEXT/PLAIN; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8BIT Hi all, On Wed, 14 Feb 2007, Jan Engelhardt wrote: > > On Feb 14 2007 16:10, sfaibish wrote: >>> >>> 1. DualFS has only one copy of every meta-data block. This copy is >>> in the meta-data device, > > Where does this differ from typical filesystems like xfs? > At least ext3 and xfs have an option to store the log/journal > on another device too. No, it is not the same. DualFS uses two 'logical' devices, one for data, and one for meta-data, but these devices are usually partitions on the same disk, they are not two different disks. And DualFS uses the meta-data device to both read and write meta-data blocks, whereas the other journaling file systems only use the log to write meta-data. It's true that XFS, Ext3 and other journaling file systems can use a separate disk for the log, but, even then, they have to write two copies of every meta-data element. However, in this case, DualFS is even better. If the data and meta-data devices of DualFS can be on different disks, DualFS is able to READ and WRITE data and meta-data blocks in PARALLEL. The other journaling file systems, however, can only write one of the two copies of every meta-data block in parallel to other file systems operations, but they can not write the second copy, and read and write data and meta-data blocks, in parallel. > >>> The DualFS code, tools and performance papers are available at: >>> >>> >>> >>> The code requires kernel patches to 2.4.19 (oldies but goodies) and >>> a separate fsck code. The latest kernel we used it for is 2.6.11 >>> and we hope with you help to port it to the latest Linux kernel. > > Where is the patch for 2.6.11? Sorry, 2.4.19 is just too old (even if > only considering the 2.4 branch). > [ And perhaps "goldies" flew better with "oldies" ;-) ] > The patch for 2.6.11 is not still stable enough to be released. Be patient ;-) Juan. > > Jan > -- D. Juan Piernas C?novas Departamento de Ingenier?a y Tecnolog?a de Computadores Facultad de Inform?tica. Universidad de Murcia Campus de Espinardo - 30080 Murcia (SPAIN) Tel.: +34968367657 Fax: +34968364151 email: piernas@ditec.um.es PGP public key: http://pgp.rediris.es:11371/pks/lookup?search=piernas%40ditec.um.es&op=index *** Por favor, env?eme sus documentos en formato texto, HTML, PDF o PostScript :-) *** --916140492-708553444-1171564694=:19998-- - 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/