From owner-freebsd-hackers@FreeBSD.ORG  Wed Jun 27 19:12:26 2012
Return-Path: <owner-freebsd-hackers@FreeBSD.ORG>
Delivered-To: freebsd-hackers@FreeBSD.org
Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52])
	by hub.freebsd.org (Postfix) with ESMTP id 0B782106566B;
	Wed, 27 Jun 2012 19:12:26 +0000 (UTC)
	(envelope-from marcel@xcllnt.net)
Received: from mail.xcllnt.net (mail.xcllnt.net [70.36.220.4])
	by mx1.freebsd.org (Postfix) with ESMTP id D38688FC1E;
	Wed, 27 Jun 2012 19:12:25 +0000 (UTC)
Received: from marcelm-sslvpn-nc.jnpr.net (natint3.juniper.net [66.129.224.36])
	(authenticated bits=0)
	by mail.xcllnt.net (8.14.5/8.14.5) with ESMTP id q5RJCLDo012105
	(version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NO);
	Wed, 27 Jun 2012 12:12:25 -0700 (PDT)
	(envelope-from marcel@xcllnt.net)
Mime-Version: 1.0 (Apple Message framework v1278)
Content-Type: text/plain; charset=us-ascii
From: Marcel Moolenaar <marcel@xcllnt.net>
In-Reply-To: <20120627182038.GB1401@garage.freebsd.pl>
Date: Wed, 27 Jun 2012 12:12:15 -0700
Content-Transfer-Encoding: quoted-printable
Message-Id: <17E70D3D-1F05-4EF2-9E66-CDCA65329EF2@xcllnt.net>
References: <4FE9B01C.30306@yandex.ru> <201206261337.11741.jhb@freebsd.org>
	<468988EA-AC50-451D-ACE1-17B58E0CAF67@xcllnt.net>
	<20120627182038.GB1401@garage.freebsd.pl>
To: Pawel Jakub Dawidek <pjd@FreeBSD.org>
X-Mailer: Apple Mail (2.1278)
Cc: Doug Rabson <dfr@FreeBSD.org>, John Baldwin <jhb@FreeBSD.org>,
	freebsd-hackers <freebsd-hackers@FreeBSD.org>,
	Andriy Gapon <avg@FreeBSD.org>,
	freebsd-current <freebsd-current@FreeBSD.org>,
	"Andrey V. Elsukov" <bu7cher@yandex.ru>
Subject: Re: [CFC/CFT] large changes in the loader(8) code
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Technical Discussions relating to FreeBSD
	<freebsd-hackers.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>, 
	<mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
	<mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 27 Jun 2012 19:12:26 -0000


On Jun 27, 2012, at 11:20 AM, Pawel Jakub Dawidek wrote:

> On Wed, Jun 27, 2012 at 10:37:11AM -0700, Marcel Moolenaar wrote:
>>=20
>> On Jun 26, 2012, at 10:37 AM, John Baldwin wrote:
>>>=20
>>> GPT really wants the backup header at the last LBA.  I know you can =
set it,=20
>>> but I've interpreted that as a way to see if the primary header is =
correct or=20
>>> not.  It seems to me that GPT tables created in this fashion (inside =
a GEOM=20
>>> provider) will not work properly with partition editors for other =
OS's.  I'm=20
>>> hesitant to encourage the use of this as I do think putting GPT =
inside of a=20
>>> gmirror violates the GPT spec.
>>=20
>> Agreed.
>=20
> Guys. This doesn't violate the GPT spec in any way. The spec is
> narrow-minded if it talks only about raw disks, but you should think
> about gmirror as pseudo-hardware RAID.

I'm sorry, but this is a contradiction. If it doesn't violate the
spec, then the spec is not narrow-minded on the grounds of what
we're discussing. If the spec *is* narrow-minded then obviously
it doesn't capture our scenario, which means that we're violating
the spec.

Clearly we're not discussing anything that falls well within the
spec, or is undebatable. This makes the whole topic dangerous
anyway. When you're in the grey area (this is only for argument's
sake -- we're in violation for sure) you're opening yourself up to
compatibility problems. Should we deliberately go there?

--=20
Marcel Moolenaar
marcel@xcllnt.net