From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262762AbTLJA7y (ORCPT ); Tue, 9 Dec 2003 19:59:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262765AbTLJA7y (ORCPT ); Tue, 9 Dec 2003 19:59:54 -0500 Received: from adsl-67-114-19-185.dsl.pltn13.pacbell.net ([67.114.19.185]:59582 "EHLO bastard") by vger.kernel.org with ESMTP id S262762AbTLJA7w (ORCPT ); Tue, 9 Dec 2003 19:59:52 -0500 Message-ID: <3FD67005.6060606@tupshin.com> Date: Tue, 09 Dec 2003 16:59:49 -0800 From: Tupshin Harper User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.6b) Gecko/20031205 Thunderbird/0.4 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Jose Luis Domingo Lopez Cc: linux-kernel@vger.kernel.org Subject: Re: Device-mapper submission for 2.4 References: <20031210002737.GA27208@localhost> In-Reply-To: <20031210002737.GA27208@localhost> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Jose Luis Domingo Lopez wrote: >On Tuesday, 09 December 2003, at 23:46:13 +0000, >Paul Jakma wrote: > > > >>There are people who store their data in LVM, we need compatibility, >>and ideally we'd like to be able to migrate in small steps. >> >> >> >Install "module-init-tools", install "LVM2" (that can drive both LVM1 >and DM Logical Volumes), compile a 2.6.x Linux kernel, reboot and you >should be done. > >As far as I remember, migration is just that easy, and you can always go >back to plain 2.4.x while you don't update LVM metadata to newer version 2. > >Greetings. > > > This is not true. LVM2 can read the LVM1 format, but it cannot communicate with non-dm interfaces in 2.4.x. This means that you need to run lvm1 on 2.4 and lvm2 on 2.6 unless you patch 2.4 with dm. If this were the whole story, then it would be an amazingly painful transition to (safely) upgrade an lvm machine from 2.4 to 2.6 (upgrade to patched 2.4, then upgrade to 2.6). Luckily, debian has made the lvm1 and lvm2 packages not conflict, and the correct ones runs at startup depending on which kernel you have. This is probably a feature that all distros will have to adopt to ease the upgrade cycle. -Tupshin