From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933167AbYECSB7 (ORCPT ); Sat, 3 May 2008 14:01:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932272AbYECSBq (ORCPT ); Sat, 3 May 2008 14:01:46 -0400 Received: from brmea-mail-4.Sun.COM ([192.18.98.36]:44916 "EHLO brmea-mail-4.sun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932257AbYECSBp (ORCPT ); Sat, 3 May 2008 14:01:45 -0400 Date: Sat, 03 May 2008 13:59:46 -0400 From: David Collier-Brown Subject: Offtopic to: LogFS merge In-reply-to: To: Linus Torvalds Cc: Willy Tarreau , =?ISO-8859-1?Q?J=F6rn_Engel?= , Stephen Rothwell , Andrew Morton , David Woodhouse , Arnd Bergmann , linux-kernel@vger.kernel.org Reply-to: davecb@sun.com Message-id: <481CA812.2030404@sun.com> MIME-version: 1.0 Content-type: text/plain; format=flowed; charset=us-ascii Content-transfer-encoding: 7BIT X-Accept-Language: en-us, en References: <20080502133234.GA24080@logfs.org> <20080502202151.GB24080@logfs.org> <20080502213146.GD24080@logfs.org> <20080502215833.GG24080@logfs.org> <20080503070318.GR8474@1wt.eu> User-Agent: Mozilla/5.0 (X11; U; SunOS sun4u; en-US; rv:1.7) Gecko/20041221 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Linus Torvalds wrote: > The real issue for me wrt a filesystem is the on-disk layout. > > If we know that on-disk structures need change, we shouldn't merge it. It > doesn't matter if that can be worked around with some backwards- > compatibiltiy flag: we should simply not encourage that kind of behaviour. I agree in particular, but not in principle (;-)) Changing the filesystem format was something that happened at least twice on Multics, on production machines. I happened to be on during one of the changes and didn't even know it was happening until there was a broadcast message warning of poor performance. I always thought that was cool, and got permission recently to post a colleague's paper on it at http://www.multicians.org/stachour.html It would be cool if data could change at run-time on Linux, just like security-sensitive code. --dave -- David Collier-Brown | Always do right. This will gratify Sun Microsystems, Toronto | some people and astonish the rest davecb@sun.com | -- Mark Twain (905) 943-1983, cell: (647) 833-9377, (800) 555-9786 x56583 bridge: (877) 385-4099 code: 506 9191#