From owner-freebsd-stable@FreeBSD.ORG Mon Feb 28 16:55:14 2011 Return-Path: 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 439051065677 for ; Mon, 28 Feb 2011 16:55:14 +0000 (UTC) (envelope-from cliftonr@oz.volcano.org) Received: from hrndva-omtalb.mail.rr.com (hrndva-omtalb.mail.rr.com [71.74.56.124]) by mx1.freebsd.org (Postfix) with ESMTP id 656DE8FC20 for ; Mon, 28 Feb 2011 16:55:08 +0000 (UTC) X-Authority-Analysis: v=1.1 cv=3uSaImBeuprzHBlOOPjkqgu+7PcxSRW0m2Aphm9Zmck= c=1 sm=0 a=6R0BXTaMqiEA:10 a=kj9zAlcOel0A:10 a=G5OLwwqwWgs+1dCEPNHTSw==:17 a=6I5d2MoRAAAA:8 a=jb__rZ8GAAAA:8 a=H9iEQFZ8AAAA:8 a=FYktocSE-NT4r9RigYoA:9 a=rgTvh_llIcvb31861CUA:7 a=mr_pZeCKQL0A9u4xJPQsBY15CncA:4 a=CjuIK1q_8ugA:10 a=sHp_62vNEjwA:10 a=fZFZujrNNEQA:10 a=G5OLwwqwWgs+1dCEPNHTSw==:117 X-Cloudmark-Score: 0 X-Originating-IP: 75.80.196.236 Received: from [75.80.196.236] ([75.80.196.236:43830] helo=oz.volcano.org) by hrndva-oedge04.mail.rr.com (envelope-from ) (ecelerity 2.2.3.46 r()) with ESMTP id 15/16-04612-B63DB6D4; Mon, 28 Feb 2011 16:55:08 +0000 Received: by oz.volcano.org (Postfix, from userid 1001) id CD80F50824; Mon, 28 Feb 2011 06:55:06 -1000 (HST) Date: Mon, 28 Feb 2011 06:55:06 -1000 From: Clifton Royston To: Marin Atanasov Nikolov Message-ID: <20110228165506.GA61412@lava.net> Mail-Followup-To: Marin Atanasov Nikolov , "Andrey V. Elsukov" , Johan Hendriks , freebsd-stable@freebsd.org References: <4D694336.3090203@yandex.ru> <57200BF94E69E54880C9BB1AF714BBCBDD318F@w2003s01.double-l.local> <4D6B96E4.1050709@yandex.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.3i Cc: "Andrey V. Elsukov" , freebsd-stable@freebsd.org, Johan Hendriks Subject: Re: 8.2-RELEASE - gmirror and gpart issue. Metadata overlap? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 28 Feb 2011 16:55:14 -0000 On Mon, Feb 28, 2011 at 06:23:10PM +0200, Marin Atanasov Nikolov wrote: > 2011/2/28 Andrey V. Elsukov : > > On 28.02.2011 11:54, Johan Hendriks wrote: > >> I opened a discussion on this before the release. > >> http://lists.freebsd.org/pipermail/freebsd-stable/2011-January/061184.ht > >> ml > >> On my 8.1 system, i get this message about the corrupt headers, but it > >> booted on the 8.2 system it panics... > >> > >> I think a lot of people are going to get bit by this. > >> > >> As far as i know there is no warning anywhere that you can not use gpart > >> and gmirror the whole disk. > > > > I can confirm as well that I get kernel panic if I gpart and then > gmirror a disk on 8.2-RELEASE. > > To reproduce it, I just did the following: > > 1) Boot a system with a Fixit image > 2) Remove all gpart partitions > 3) gpart the first disk (ad0) > 4) Restored my data to the partitions from backups > 5) Reboot > 6) gmirror the ad0 disk > > And that's where I got kernel panic. > > gpart'ing the disk and the mirroring the partitions works just as > fine, but not when you mirror the whole disk. I think this only ever worked accidentally at best. It would work fine with the older fdisk-style disk partition because that doesn't touch the end of the disk, but any time you tell two different programs that they both have absolute control over the last sector on the disk and can write critical data there - which is what this is doing - that's begging for trouble. Something cleaner than a kernel panic would be *nice* however... And your point about warnings in the documentation is a good one. -- Clifton -- Clifton Royston -- cliftonr@iandicomputing.com / cliftonr@lava.net President - I and I Computing * http://www.iandicomputing.com/ Custom programming, network design, systems and network consulting services