From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753689AbXDPWeu (ORCPT ); Mon, 16 Apr 2007 18:34:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753955AbXDPWeu (ORCPT ); Mon, 16 Apr 2007 18:34:50 -0400 Received: from mga06.intel.com ([134.134.136.21]:8711 "EHLO orsmga101.jf.intel.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753689AbXDPWet (ORCPT ); Mon, 16 Apr 2007 18:34:49 -0400 X-ExtLoop1: 1 X-IronPort-AV: i="4.14,415,1170662400"; d="scan'208"; a="228536811:sNHT18609920" Date: Mon, 16 Apr 2007 15:34:42 -0700 From: Valerie Henson To: David Chinner Cc: Rik van Riel , "David R. Litwin" , linux-kernel@vger.kernel.org Subject: Repair-driven file system design (was Re: ZFS with Linux: An Open Plea) Message-ID: <20070416223440.GA18590@nifty> References: <4622C851.2030509@redhat.com> <20070416030705.GY32602149@melbourne.sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070416030705.GY32602149@melbourne.sgi.com> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 16, 2007 at 01:07:05PM +1000, David Chinner wrote: > On Sun, Apr 15, 2007 at 08:50:25PM -0400, Rik van Riel wrote: > > > IMHO chunkfs could provide a much more promising approach. > > Agreed, that's one method of compartmentalising the problem..... Agreed, the chunkfs design is only one way to implement repair-driven file system design - designing your file system to make file system check and repair fast and easy. I've written a paper on this idea, which includes some interesting projections estimating that fsck will take 10 times as long on the 2013 equivalent of a 2006 file system, due entirely to changes in disk hardware. So if your server currently takes 2 hours to fsck, an equivalent server in 2013 will take about 20 hours. Eek! Paper here: http://infohost.nmt.edu/~val/review/repair.pdf While I'm working on chunkfs, I also think that all file systems should strive for repair-driven design. XFS has already made big strides in this area (multi-threading fsck for multi-disk file systems, for example) and I'm excited to see what comes next. -VAL