From owner-freebsd-stable@FreeBSD.ORG  Thu Apr 28 15:43:14 2011
Return-Path: <owner-freebsd-stable@FreeBSD.ORG>
Delivered-To: freebsd-stable@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id B7E0B106566B
	for <freebsd-stable@freebsd.org>; Thu, 28 Apr 2011 15:43:14 +0000 (UTC)
	(envelope-from petefrench@ingresso.co.uk)
Received: from constantine.ingresso.co.uk (constantine.ingresso.co.uk
	[IPv6:2001:470:1f09:176e::3])
	by mx1.freebsd.org (Postfix) with ESMTP id 801CC8FC16
	for <freebsd-stable@freebsd.org>; Thu, 28 Apr 2011 15:43:14 +0000 (UTC)
Received: from dilbert.london-internal.ingresso.co.uk ([10.64.50.6]
	helo=dilbert.ingresso.co.uk)
	by constantine.ingresso.co.uk with esmtps (TLSv1:AES256-SHA:256)
	(Exim 4.73 (FreeBSD)) (envelope-from <petefrench@ingresso.co.uk>)
	id 1QFTMy-000EEB-DI; Thu, 28 Apr 2011 16:43:08 +0100
Received: from petefrench by dilbert.ingresso.co.uk with local (Exim 4.74
	(FreeBSD)) (envelope-from <petefrench@ingresso.co.uk>)
	id 1QFTMy-000JA0-9I; Thu, 28 Apr 2011 16:43:08 +0100
To: edhoprima@gmail.com, fjwcash@gmail.com
In-Reply-To: <BANLkTimAxZNrT63kDOPTN+q1wOoQqf3Q5g@mail.gmail.com>
Message-Id: <E1QFTMy-000JA0-9I@dilbert.ingresso.co.uk>
From: Pete French <petefrench@ingresso.co.uk>
Date: Thu, 28 Apr 2011 16:43:08 +0100
Cc: freebsd-stable@freebsd.org, daniel@digsys.bg
Subject: Re: correct way to setup gmirror on 7.4?
X-BeenThere: freebsd-stable@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Production branch of FreeBSD source code <freebsd-stable.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>, 
	<mailto:freebsd-stable-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-stable>
List-Post: <mailto:freebsd-stable@freebsd.org>
List-Help: <mailto:freebsd-stable-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>,
	<mailto:freebsd-stable-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 28 Apr 2011 15:43:14 -0000

> Correct.  The layering is not, in itself, the issue.  The issue is
> that the loader or kernel or whatever reads the first sector of the
> disk, finds a GPT so it then looks for the backup GPT in the last
> physical sector of the disk and doesn't find it.  At this point,
> gmirror is not loaded (or not noticed, since there's nothing in the
> first sector of the disk to show it's a mirror).  Once gmirror is
> loaded, then the GPT stops complaining as the first and last sectors
> of the gmirrror provider have the GPT tables.

Is not the problem here that you are trying to GPT label a gmirrored disc ?
If you instead gmirror two GPT partitions then the problem goes away
doesnt it ? Thats how I set things up - use parititoning on the ohysical
drives, and then put the mirroring into the partitions thus created.
Works fine, and doesnt suffer from any of the afforementioned problems.

-pete.