From owner-freebsd-fs@FreeBSD.ORG  Fri Nov 16 15:45:28 2012
Return-Path: <owner-freebsd-fs@FreeBSD.ORG>
Delivered-To: freebsd-fs@FreeBSD.org
Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52])
 by hub.freebsd.org (Postfix) with ESMTP id 2FC9EA0B;
 Fri, 16 Nov 2012 15:45:28 +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 2CDE98FC1A;
 Fri, 16 Nov 2012 15:45:26 +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 RAA17441;
 Fri, 16 Nov 2012 17:45:08 +0200 (EET) (envelope-from avg@FreeBSD.org)
Message-ID: <50A65F83.5000604@FreeBSD.org>
Date: Fri, 16 Nov 2012 17:45:07 +0200
From: Andriy Gapon <avg@FreeBSD.org>
User-Agent: Mozilla/5.0 (X11; FreeBSD amd64;
 rv:16.0) Gecko/20121029 Thunderbird/16.0.2
MIME-Version: 1.0
To: Guido Falsi <mad@madpilot.net>, Bartosz Stec <bartosz.stec@it4pro.pl>
Subject: problem booting to multi-vdev root pool [Was: kern/150503: [zfs]
 ZFS disks are UNAVAIL and corrupted after reboot]
References: <509D1DEC.6040505@FreeBSD.org> <50A27243.408@madpilot.net>
In-Reply-To: <50A27243.408@madpilot.net>
X-Enigmail-Version: 1.4.5
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Cc: freebsd-fs@FreeBSD.org, freebsd-current@FreeBSD.org
X-BeenThere: freebsd-fs@freebsd.org
X-Mailman-Version: 2.1.14
Precedence: list
List-Id: Filesystems <freebsd-fs.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/freebsd-fs>,
 <mailto:freebsd-fs-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-fs>
List-Post: <mailto:freebsd-fs@freebsd.org>
List-Help: <mailto:freebsd-fs-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-fs>,
 <mailto:freebsd-fs-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 16 Nov 2012 15:45:28 -0000

on 13/11/2012 18:16 Guido Falsi said the following:
> My idea, but is just a speculation, i could be very wrong, is that the geom
> tasting code has some problem with multiple vdev root pools.

Guido,

you are absolutely correct.  The code for reconstructing/tasting a root pool
configuration is a modified upstream code, so it inherited a limitation from it:
the support for only a single top-level vdev in a root pool.
I have an idea how to add the missing support, but it turned out not to be
something that I can hack together in couple of hours.

So, instead I wrote the following patch that should fall back to using a root pool
configuration from zpool.cache (if it's present there) for a multi-vdev root pool:
http://people.freebsd.org/~avg/zfs-spa-multi_vdev_root_fallback.diff

The patch also fixes a minor (single-time) memory leak.

Guido, Bartosz,
could you please test the patch?

Apologies for the breakage.

-- 
Andriy Gapon