From owner-freebsd-current@FreeBSD.ORG Mon Jul 20 22:44:48 2009 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 8F2FE1065670 for ; Mon, 20 Jul 2009 22:44:48 +0000 (UTC) (envelope-from ari@ish.com.au) Received: from fish.ish.com.au (eth5921.nsw.adsl.internode.on.net [59.167.240.32]) by mx1.freebsd.org (Postfix) with ESMTP id 271068FC16 for ; Mon, 20 Jul 2009 22:44:47 +0000 (UTC) (envelope-from ari@ish.com.au) Received: from [10.29.62.4] (port=62665 helo=Aris-MacBook-Pro.local) by fish.ish.com.au with esmtpa (Exim 4.69) (envelope-from ) id 1MT2fq-0006nI-2S; Tue, 21 Jul 2009 09:53:38 +1000 Message-ID: <4A64F35E.6070501@ish.com.au> Date: Tue, 21 Jul 2009 08:44:46 +1000 From: Aristedes Maniatis User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.1.1pre) Gecko/20090714 Shredder/3.0b3pre MIME-Version: 1.0 To: Kip Macy References: <4A5D4D25.3040908@ish.com.au> <3c1674c90907201501j42f29bfbl987419edf04b1a8b@mail.gmail.com> In-Reply-To: <3c1674c90907201501j42f29bfbl987419edf04b1a8b@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-current@freebsd.org, Jurgen Weber Subject: Re: Problematic upgrade from 7.2 to 8.0 with ZFS file system X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 20 Jul 2009 22:44:48 -0000 On 21/07/09 8:01 AM, Kip Macy wrote: >> The other solution is to install userland BEFORE you reboot into the new >> > kernel, although that may cause its own set of problems. Whatever the final >> > solution, this needs to be clearly documented and ideally freebsd-update >> > needs to detect the problem and advise the user about what to do. > > > Do to the large version jump (v6 -> v13) the kernel interfaces aren't > backward compatible with the tools. How do you think it could be most > gracefully handled? I honestly don't know how the right way to solve the problem, but here are some ideas: * the kernel ABI *should* be compatible with userland tools at least one major version backward. I understand that this might now be impossible, but it is possible to bring back enough of the old ABI to allow for zfs to mount? * freebsd-update could automatically detect this situation and install the new zfs userland at the same time as the new kernel * lots of of clear documentation about what course of action a user should follow if they are performing a source update. Should the recommendation be changed to install userland *before* rebooting, and then immediately reboot before some of that userland explodes against the old kernel in memory? The existing recommendation is based on the fact that the new kernel will continue to work after reboot with the old userland. If that assumption is not always true then the whole FreeBSD installation process needs rethinking. Ari Maniatis --------------------------> ish http://www.ish.com.au Level 1, 30 Wilson Street Newtown 2042 Australia phone +61 2 9550 5001 fax +61 2 9550 4001 GPG fingerprint CBFB 84B4 738D 4E87 5E5C 5EFA EF6A 7D2E 3E49 102A