From owner-freebsd-stable@FreeBSD.ORG Wed Nov 28 18:35:58 2012 Return-Path: Delivered-To: freebsd-stable@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 90D37C51; Wed, 28 Nov 2012 18:35:58 +0000 (UTC) (envelope-from avg@FreeBSD.org) Received: from citadel.icyb.net.ua (citadel.icyb.net.ua [212.40.38.140]) by mx1.freebsd.org (Postfix) with ESMTP id B08368FC16; Wed, 28 Nov 2012 18:35:57 +0000 (UTC) Received: from odyssey.starpoint.kiev.ua (alpha-e.starpoint.kiev.ua [212.40.38.101]) by citadel.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id UAA29309; Wed, 28 Nov 2012 20:35:56 +0200 (EET) (envelope-from avg@FreeBSD.org) Message-ID: <50B6598B.20200@FreeBSD.org> Date: Wed, 28 Nov 2012 20:35:55 +0200 From: Andriy Gapon User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: FreeBSD current , FreeBSD Stable Subject: [HEADSUP] zfs root pool mounting X-Enigmail-Version: 1.4.6 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 28 Nov 2012 18:35:58 -0000 Recently some changes were made to how a root pool is opened for root filesystem mounting. Previously the root pool had to be present in zpool.cache. Now it is automatically discovered by probing available GEOM providers. The new scheme is believed to be more flexible. For example, it allows to prepare a new root pool at one system, then export it and then boot from it on a new system without doing any extra/magical steps with zpool.cache. It could also be convenient after zpool split and in some other situations. The change was introduced via multiple commits, the latest relevant revision in head is r243502. The changes are partially MFC-ed, the remaining parts are scheduled to be MFC-ed soon. I have received a report that the change caused a problem with booting on at least one system. The problem has been identified as an issue in local environment and has been fixed. Please read on to see if you might be affected when you upgrade, so that you can avoid any unnecessary surprises. You might be affected if you ever had a pool named the same as your current root pool. And you still have any disks connected to your system that belonged to that pool (in whole or via some partitions). And that pool was never properly destroyed using zpool destroy, but merely abandoned (its disks re-purposed/re-partitioned/reused). If all of the above are true, then I recommend that you run 'zdb -l ' for all suspect disks and their partitions (or just all disks and partitions). If this command reports at least one valid ZFS label for a disk or a partition that do not belong to any current pool, then the problem may affect you. The best course is to remove the offending labels. If you are affected, please follow up to this email. -- Andriy Gapon