From owner-freebsd-stable@FreeBSD.ORG Thu Mar 16 16:08:48 2006 Return-Path: X-Original-To: stable@freebsd.org Delivered-To: freebsd-stable@FreeBSD.ORG Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 4C49316A420 for ; Thu, 16 Mar 2006 16:08:48 +0000 (UTC) (envelope-from craig@feniz.gank.org) Received: from ion.gank.org (ion.gank.org [69.55.238.164]) by mx1.FreeBSD.org (Postfix) with ESMTP id 134B843D45 for ; Thu, 16 Mar 2006 16:08:47 +0000 (GMT) (envelope-from craig@feniz.gank.org) Received: by ion.gank.org (Postfix, from userid 1001) id A1931117B8; Thu, 16 Mar 2006 10:08:47 -0600 (CST) Date: Thu, 16 Mar 2006 10:08:45 -0600 From: Craig Boston To: Freddie Cash Message-ID: <20060316160813.GA15720@nowhere> Mail-Followup-To: Craig Boston , Freddie Cash , stable@freebsd.org References: <440D74B3.3030309@vwsoft.com> <200603070939.30032.joao@matik.com.br> <54559.192.168.0.10.1141751042.squirrel@webmail.sd73.bc.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <54559.192.168.0.10.1141751042.squirrel@webmail.sd73.bc.ca> User-Agent: Mutt/1.4.2.1i Cc: stable@freebsd.org Subject: gmirror on existing filesystem (was Fresh install on gmirror'ed disks?) 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: Thu, 16 Mar 2006 16:08:48 -0000 On Tue, Mar 07, 2006 at 09:04:02AM -0800, Freddie Cash wrote: > There's no need to copy files around. gmirror handles it all for you > behind the scenes. Just create the gmirror labels using the existing > disks/slices/partitions, then insert the second set of > disks/slices/parittions. gmirror will handle synchonising the data > across the mirror. AFAIK, gmirror causes whatever provider it's mirroring to "lose" the last block to metadata. I've always avoided mirroring an existing filesystem for fear that shrinking a UFS filesystem's underlying device might cause problems down the road. Can someone with knowledge of the UFS internals please confirm one way or the other if this is dangerous or not? Craig