From owner-freebsd-current@FreeBSD.ORG Thu May 10 22:46:06 2007 Return-Path: X-Original-To: freebsd-current@freebsd.org Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 68A6C16A400 for ; Thu, 10 May 2007 22:46:06 +0000 (UTC) (envelope-from bakul@bitblocks.com) Received: from mail.bitblocks.com (ns1.bitblocks.com [64.142.15.60]) by mx1.freebsd.org (Postfix) with ESMTP id 4C82B13C447 for ; Thu, 10 May 2007 22:46:06 +0000 (UTC) (envelope-from bakul@bitblocks.com) Received: from bitblocks.com (localhost.bitblocks.com [127.0.0.1]) by mail.bitblocks.com (Postfix) with ESMTP id C05365B5A; Thu, 10 May 2007 15:46:05 -0700 (PDT) To: efinley@efinley.com In-reply-to: Your message of "Thu, 10 May 2007 14:31:45 MDT." Date: Thu, 10 May 2007 15:46:05 -0700 From: Bakul Shah Message-Id: <20070510224605.C05365B5A@mail.bitblocks.com> Cc: freebsd-current@freebsd.org Subject: Re: ZFS the perfect FS? if only... X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 10 May 2007 22:46:06 -0000 > If you could start with a 3 drive zraid2 as the underlying pool > storage and later add drives to the existing zraid2 as space was > needed, then ZFS would be the ultimate FS (at least for me). > > Any takers? How hard would this be? You can do something like this: zpool create foo raidz2 dev0 dev1 dev2 dev3 zpool add foo raidz2 dev4 dev5 dev6 dev7 The new devices are in a different raidz2 group but but *all of the space* will be used for any filesystem on this pool -- isn't this good enough and if not, why? If you add a new disk to the same raid, you have to redistirbute most data. Not worth it Note you need at least 3 disks for raidz and 4 disks for raidz2. In general you want to put almost all your disks in a single pool but not in a single mirror, raidz or raidz2. Root zfs should be in its own pool and perhaps databases. See http://www.solarisinternals.com/wiki/index.php/ZFS_Best_Practices_Guide