From owner-freebsd-stable@FreeBSD.ORG Tue Jun 5 16:02:42 2007 Return-Path: X-Original-To: freebsd-stable@FreeBSD.ORG Delivered-To: freebsd-stable@FreeBSD.ORG Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id BCE8116A400 for ; Tue, 5 Jun 2007 16:02:42 +0000 (UTC) (envelope-from olli@lurza.secnetix.de) Received: from lurza.secnetix.de (lurza.secnetix.de [83.120.8.8]) by mx1.freebsd.org (Postfix) with ESMTP id 4291013C45A for ; Tue, 5 Jun 2007 16:02:42 +0000 (UTC) (envelope-from olli@lurza.secnetix.de) Received: from lurza.secnetix.de (naxydi@localhost [127.0.0.1]) by lurza.secnetix.de (8.13.4/8.13.4) with ESMTP id l55G2ZN3063227; Tue, 5 Jun 2007 18:02:40 +0200 (CEST) (envelope-from oliver.fromme@secnetix.de) Received: (from olli@localhost) by lurza.secnetix.de (8.13.4/8.13.1/Submit) id l55G2Zwq063226; Tue, 5 Jun 2007 18:02:35 +0200 (CEST) (envelope-from olli) Date: Tue, 5 Jun 2007 18:02:35 +0200 (CEST) Message-Id: <200706051602.l55G2Zwq063226@lurza.secnetix.de> From: Oliver Fromme To: freebsd-stable@FreeBSD.ORG, ubm@u-boot-man.de In-Reply-To: <20070605170345.3df2b8ef.ubm@u-boot-man.de> X-Newsgroups: list.freebsd-stable User-Agent: tin/1.8.2-20060425 ("Shillay") (UNIX) (FreeBSD/4.11-STABLE (i386)) MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-2.1.2 (lurza.secnetix.de [127.0.0.1]); Tue, 05 Jun 2007 18:02:40 +0200 (CEST) Cc: Subject: Re: gmirror on a disk with data already on it X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: freebsd-stable@FreeBSD.ORG, ubm@u-boot-man.de List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 05 Jun 2007 16:02:42 -0000 Marc UBM Bocklet wrote: > The gmirror man page says that if gmirror is used on a disk, the last > sector of that disk is overwritten with the metadata gmirror uses. > > So what I would like to know is, how risky is it to mirror a disk which > already has data on it? > > Is there a chance that I might render my system unbootable? If you follow the procedure in the Handbook, then there is no risk at all. It involves preparing one side of the mirror on the second (unused) device first, then attaching the first device to the mirror. Best regards Oliver -- Oliver Fromme, secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing b. M. Handelsregister: Registergericht Muenchen, HRA 74606, Geschäftsfuehrung: secnetix Verwaltungsgesellsch. mbH, Handelsregister: Registergericht Mün- chen, HRB 125758, Geschäftsführer: Maik Bachmann, Olaf Erb, Ralf Gebhart FreeBSD-Dienstleistungen, -Produkte und mehr: http://www.secnetix.de/bsd "With sufficient thrust, pigs fly just fine. However, this is not necessarily a good idea. It is hard to be sure where they are going to land, and it could be dangerous sitting under them as they fly overhead." -- RFC 1925