From owner-freebsd-fs@FreeBSD.ORG Thu Jul 19 10:45:59 2007 Return-Path: X-Original-To: freebsd-fs@freebsd.org Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id BFD3716A400 for ; Thu, 19 Jul 2007 10:45:59 +0000 (UTC) (envelope-from M.S.Powell@salford.ac.uk) Received: from akis.salford.ac.uk (akis.salford.ac.uk [146.87.0.14]) by mx1.freebsd.org (Postfix) with SMTP id 40BEA13C491 for ; Thu, 19 Jul 2007 10:45:53 +0000 (UTC) (envelope-from M.S.Powell@salford.ac.uk) Received: (qmail 4947 invoked by uid 98); 19 Jul 2007 11:19:11 +0100 Received: from 146.87.255.121 by akis.salford.ac.uk (envelope-from , uid 401) with qmail-scanner-2.01 (clamdscan: 0.90/3697. spamassassin: 3.1.8. Clear:RC:1(146.87.255.121):. Processed in 0.043798 secs); 19 Jul 2007 10:19:11 -0000 Received: from rust.salford.ac.uk (HELO rust.salford.ac.uk) (146.87.255.121) by akis.salford.ac.uk (qpsmtpd/0.3x.614) with SMTP; Thu, 19 Jul 2007 11:19:11 +0100 Received: (qmail 1880 invoked by uid 1002); 19 Jul 2007 10:19:08 -0000 Received: from localhost (sendmail-bs@127.0.0.1) by localhost with SMTP; 19 Jul 2007 10:19:08 -0000 Date: Thu, 19 Jul 2007 11:19:08 +0100 (BST) From: "Mark Powell" To: freebsd-fs@freebsd.org Message-ID: <20070719102302.R1534@rust.salford.ac.uk> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Subject: ZfS & GEOM with many odd drive sizes X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 19 Jul 2007 10:45:59 -0000 Hi, I'd like to experiment with ZFS. To that end I'd like to get a running array from a rather ad hoc collection of old drives. 3x250GB 3x200GB 1x400GB I planned to arrange them in 3 pairs of of 250+200. Therefore I'd end up with an effective 4 drives: 3x450GB 1x400GB I'd gmirror to make a small 2GB root and swap from the extra 50GB on the 3 pairs. Then gconcat to join the remaining 448GB from each pair into a volume. Apparently root is possible on ZFS with a small ufs to boot from: http://wiki.freebsd.org/ZFSOnRoot Then make a zfs raidz from the 3x448+1x400. Effectively giving a zpool of 1200GB real storage. 3x48GB will not be accessible now as the last volume will only be the 400GB on the last drive. I want to be able to increase the size of this volume later, by replacing drives when they fail, or it becomes economical to do so. I know removing a volume from a zpool and replacing it with a larger one is possible. The zpool will self-heal the data onto the new volume. Eventually when the final volume is replaced by a larger one the extra space becomes available for use. That's correct right? What I want to know is, does the new volume have to be the same actual device name or can it be substituted with another? i.e. can I remove, for example, one of the 448GB gconcats e.g. gc1 and replace that with a new 750GB drive e.g. ad6? Eventually so that once all volumes are replaced the zpool could be, for example, 4x750GB or 2.25TB of usable storage. Many thanks for any advice on these matters which are new to me. -- Mark Powell - UNIX System Administrator - The University of Salford Information Services Division, Clifford Whitworth Building, Salford University, Manchester, M5 4WT, UK. Tel: +44 161 295 4837 Fax: +44 161 295 5888 www.pgp.com for PGP key