Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261558AbVEMUrk (ORCPT ); Fri, 13 May 2005 16:47:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262503AbVEMUdk (ORCPT ); Fri, 13 May 2005 16:33:40 -0400 Received: from mail.uni-ulm.de ([134.60.1.1]:15611 "EHLO mail.uni-ulm.de") by vger.kernel.org with ESMTP id S262526AbVEMURO (ORCPT ); Fri, 13 May 2005 16:17:14 -0400 Date: Fri, 13 May 2005 22:18:15 +0200 From: Markus Klotzbuecher To: Kyle Moffett Cc: =?iso-8859-1?Q?J=F6rn?= Engel , linux-kernel@vger.kernel.org Subject: Re: [ANNOUNCE] mini_fo-0.6.0 overlay file system Message-ID: <20050513201814.GA8208@mary> Mail-Followup-To: Kyle Moffett , =?iso-8859-1?Q?J=F6rn?= Engel , linux-kernel@vger.kernel.org References: <20050509183135.GB27743@mary> <20050512121842.GA20388@wohnheim.fh-wedel.de> <20050512164413.GA14099@mary> <2F200E69-465D-46ED-9D3A-5ED5C9FEAC9A@mac.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2F200E69-465D-46ED-9D3A-5ED5C9FEAC9A@mac.com> User-Agent: Mutt/1.5.8i X-DCC-sgs_public_dcc_server-Metrics: gemini 1199; Body=3 Fuz1=3 Fuz2=3 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1137 Lines: 26 On Thu, May 12, 2005 at 11:18:36PM -0400, Kyle Moffett wrote: > 2) When forced to copy data, the copy should be done in the context of > whatever process is doing the "write" operation, and be interruptible, > etc. The end result is that if you union an nfs mount over another one, > it will just seem like a write to a big file takes a _really_ long time > to complete. This is what happens with mini_fo, provided your kernel is preemptive. > 3) ext2/3 should get an extra flag for files and directories that > indicates nonresidence. This would be used by the VFS union layer to [...] I like the idea of copying modified data on a per block basis. This really would avoid unnecessary long copy operations and potentially save a lot of storage. But I think a unifying layer should not rely on specialities such as sparse files or flags provided by the lower layer file systems. Markus - 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/