From owner-freebsd-stable@FreeBSD.ORG Fri Jul 23 00:47:29 2010 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 54A761065673 for ; Fri, 23 Jul 2010 00:47:29 +0000 (UTC) (envelope-from dan@langille.org) Received: from nyi.unixathome.org (nyi.unixathome.org [64.147.113.42]) by mx1.freebsd.org (Postfix) with ESMTP id 297C48FC1F for ; Fri, 23 Jul 2010 00:47:28 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by nyi.unixathome.org (Postfix) with ESMTP id 17AAE5093D for ; Fri, 23 Jul 2010 01:47:28 +0100 (BST) X-Virus-Scanned: amavisd-new at unixathome.org Received: from nyi.unixathome.org ([127.0.0.1]) by localhost (nyi.unixathome.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id BCeG18C9JU00 for ; Fri, 23 Jul 2010 01:47:24 +0100 (BST) Received: from smtp-auth.unixathome.org (smtp-auth.unixathome.org [10.4.7.7]) (Authenticated sender: hidden) by nyi.unixathome.org (Postfix) with ESMTPSA id 993BE5089E for ; Fri, 23 Jul 2010 01:47:24 +0100 (BST) Message-ID: <4C48E695.6030602@langille.org> Date: Thu, 22 Jul 2010 20:47:17 -0400 From: Dan Langille Organization: The FreeBSD Diary User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.2.7) Gecko/20100713 Thunderbird/3.1.1 MIME-Version: 1.0 To: freebsd-stable@freebsd.org References: <4C47B57F.5020309@langille.org> In-Reply-To: <4C47B57F.5020309@langille.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: Using GTP and glabel for ZFS arrays 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: Fri, 23 Jul 2010 00:47:29 -0000 Thank you to all the helpful discussion. It's been very helpful and educational. Based on the advice and suggestions, I'm going to adjust my original plan as follows. NOTE: glabel will not be used. First, create a new GUID Partition Table partition scheme on the HDD: gpart create -s GPT ad0 Let's see how much space we have. This output will be used to determine SOMEVALUE in the next command. gpart show Create a new partition within that scheme: gpart add -b 1024 -s SOMEVALUE -t freebsd-zfs -l disk00 ad0 The -b 1024 ensures alignment on a 4KB boundary. SOMEVALUE will be set so approximately 200MB is left empty at the end of the HDD. That's part more than necessary to accommodate the different actualy size of 2TB HDD. Repeat the above with ad1 to get disk01. Repeat for all other HDD... Then create your zpool: zpool create bigtank gpt/disk00 gpt/disk02 ... etc This plan will be applied to an existing 5 HDD ZFS pool. I have two new empty HDD which will be added to this new array (giving me 7 x 2TB HDD). The array is raidz1 and I'm wondering if I want to go to raidz2. That would be about 10TB and I'm only using up 3.1TB at present. That represents about 4 months of backups. I do not think I can adjust the existing zpool on the fly. I think I need to copy everything elsewhere (i.e the 2 empty drives). Then start the new zpool from scratch. The risk: when the data is on the 2 spare HDD, there is no redundancy. I wonder if my friend Jerry has a spare 2TB HDD I could borrow for the evening. -- Dan Langille - http://langille.org/