From owner-freebsd-stable@FreeBSD.ORG Sun Jun 2 21:46:57 2013 Return-Path: <owner-freebsd-stable@FreeBSD.ORG> Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id 212DA9E5 for <freebsd-stable@freebsd.org>; Sun, 2 Jun 2013 21:46:57 +0000 (UTC) (envelope-from marck@rinet.ru) Received: from woozle.rinet.ru (woozle.rinet.ru [195.54.192.68]) by mx1.freebsd.org (Postfix) with ESMTP id A10F01A19 for <freebsd-stable@freebsd.org>; Sun, 2 Jun 2013 21:46:56 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by woozle.rinet.ru (8.14.5/8.14.5) with ESMTP id r52LktRe043028; Mon, 3 Jun 2013 01:46:55 +0400 (MSK) (envelope-from marck@rinet.ru) Date: Mon, 3 Jun 2013 01:46:55 +0400 (MSK) From: Dmitry Morozovsky <marck@rinet.ru> To: Warren Block <wblock@wonkity.com> Subject: Re: Corrupt GPT header on disk from twa array - fixable? In-Reply-To: <alpine.BSF.2.00.1306021524230.11353@wonkity.com> Message-ID: <alpine.BSF.2.00.1306030143210.48048@woozle.rinet.ru> References: <EA2DCEC2-8B07-434B-8B60-8AB15B3788F7@gmail.com> <7ABBEE71A96E411793E41BD97DA72BCE@multiplay.co.uk> <CA+7WWSe7O9+xq3UEJ++tM1d3tphf7pWU=n4DoQY8XZq39RRScQ@mail.gmail.com> <2943982C-719E-45D0-9B26-43B725738F83@gmail.com> <alpine.BSF.2.00.1306020834050.8625@wonkity.com> <3659A498-F0EA-4AF3-80EA-40038DCA9CC7@gmail.com> <alpine.BSF.2.00.1306021156010.9922@wonkity.com> <alpine.BSF.2.00.1306030120200.48048@woozle.rinet.ru> <alpine.BSF.2.00.1306021524230.11353@wonkity.com> User-Agent: Alpine 2.00 (BSF 1167 2008-08-23) X-NCC-RegID: ru.rinet X-OpenPGP-Key-ID: 6B691B03 MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.4.3 (woozle.rinet.ru [0.0.0.0]); Mon, 03 Jun 2013 01:46:55 +0400 (MSK) Cc: Kimmo Paasiala <kpaasial@gmail.com>, freebsd-stable@freebsd.org X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Production branch of FreeBSD source code <freebsd-stable.freebsd.org> List-Unsubscribe: <http://lists.freebsd.org/mailman/options/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: Sun, 02 Jun 2013 21:46:57 -0000 On Sun, 2 Jun 2013, Warren Block wrote: > > > gmirror is good. GPT is also good. The combination is a problem. gmirror > > > metadata overwrites the backup GPT, so those disks will show "corrupt" > > > also. > > > For now, the recommended workaround is to just use MBR, which doesn't have > > > any > > > metadata at the end of the disk. > > > > ... or gmirror not whole disks, but GPT partitions (as OP does, as far as I > > can > > tell from gmirror dmesg reports) > > That works, but if there is more than one partition per disk, rebuilds fight > with each other for the heads. Right; OTOH, there is usually no more than one or two partitions which are under write pressure, so *usually* you'll find rebuilding, say, /dev/mirror/var and /dev/mirror/db (at least most of our gmirror-setup servers show that) On the third hand, if you have enough memory, ZFS is both simplier and more lazy regarding repairs ;) -- Sincerely, D.Marck [DM5020, MCK-RIPE, DM3-RIPN] [ FreeBSD committer: marck@FreeBSD.org ] ------------------------------------------------------------------------ *** Dmitry Morozovsky --- D.Marck --- Wild Woozle --- marck@rinet.ru *** ------------------------------------------------------------------------