From owner-freebsd-stable@FreeBSD.ORG Mon Jun 29 15:33:02 2009 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 DF92C1065714 for ; Mon, 29 Jun 2009 15:33:01 +0000 (UTC) (envelope-from nakal@web.de) Received: from fmmailgate02.web.de (fmmailgate02.web.de [217.72.192.227]) by mx1.freebsd.org (Postfix) with ESMTP id 4E6688FC15 for ; Mon, 29 Jun 2009 15:33:01 +0000 (UTC) (envelope-from nakal@web.de) Received: from smtp08.web.de (fmsmtp08.dlan.cinetic.de [172.20.5.216]) by fmmailgate02.web.de (Postfix) with ESMTP id DEF79105B3325; Mon, 29 Jun 2009 17:32:19 +0200 (CEST) Received: from [217.236.20.4] (helo=zelda.local) by smtp08.web.de with asmtp (TLSv1:AES128-SHA:128) (WEB.DE 4.110 #277) id 1MLIqB-0001Kq-00; Mon, 29 Jun 2009 17:32:19 +0200 Date: Mon, 29 Jun 2009 17:32:17 +0200 From: Martin To: Marius =?UTF-8?B?TsO8bm5lcmljaA==?= Message-ID: <20090629173217.2bb1e6fc@zelda.local> In-Reply-To: References: <20090629094359.GB24054@hugo10.ka.punkt.de> <20090629114610.GA28731@hugo10.ka.punkt.de> <20090629141437.GD31011@hugo10.ka.punkt.de> X-Mailer: Claws Mail 3.7.1 (GTK+ 2.16.2; amd64-portbld-freebsd8.0) Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Sender: nakal@web.de X-Sender: nakal@web.de X-Provags-ID: V01U2FsdGVkX1/aq/hsN7r/FUNp4vR9yC//QBdB/jT+PEaAL0+Y 3FOi5sXwW87VZ/fgVuwd0/7Nfgd/ijujFiVNmqCLNoOX2AZz8N om1fQfRL4= Cc: FreeBSD Stable Mailing List Subject: Re: Zpool on raw disk and weird GEOM complaint 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, 29 Jun 2009 15:33:03 -0000 Am Mon, 29 Jun 2009 16:49:01 +0200 schrieb Marius N=C3=BCnnerich : > For > future constructions of zpool's one should zero the first few sectors > of a device. For your specific I would make a tested backup and then > zero the first 1KB of da0. But beware that it's dangerous! Don't blame > me if you lose data or hair! Hi Marius. I've already complained about this problem. When you've had GPT and want to remove it, you will always get endless pain, if you forget to remove the meta data (gpart destroy). And don't forget that when it is too late and you already have a file system, it's not enough to clear the first few blocks of GPT, but also the last(!) blocks on disk, because GPT has a backup table at the end of a disk that GEOM automatically tries to use. I tell you, you have a lot of "fun" with this! You have to be very cautious, not to lose any data when trying to dump zeroes on the raw disk device. The problem should be better documented, in my opinion. It took me hours of downtime (and some frustration) to find out how GEOM is tasting and detecting the disks. -- Martin