From owner-freebsd-fs@FreeBSD.ORG Wed Nov 28 09:55:27 2007 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 1693216A417 for ; Wed, 28 Nov 2007 09:55:27 +0000 (UTC) (envelope-from roberto@keltia.freenix.fr) Received: from keltia.freenix.fr (keltia.freenix.org [82.230.37.243]) by mx1.freebsd.org (Postfix) with ESMTP id BF0E713C4E1 for ; Wed, 28 Nov 2007 09:55:26 +0000 (UTC) (envelope-from roberto@keltia.freenix.fr) Received: from localhost (localhost [127.0.0.1]) by keltia.freenix.fr (Postfix/TLS) with ESMTP id 439B539650 for ; Wed, 28 Nov 2007 10:39:22 +0100 (CET) X-Virus-Scanned: amavisd-new at keltia.freenix.fr Received: from keltia.freenix.fr ([127.0.0.1]) by localhost (keltia.freenix.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id JsDO35xh3vK5 for ; Wed, 28 Nov 2007 10:39:19 +0100 (CET) Received: by keltia.freenix.fr (Postfix/TLS, from userid 101) id 7E4643964E; Wed, 28 Nov 2007 10:39:19 +0100 (CET) Date: Wed, 28 Nov 2007 10:39:19 +0100 From: Ollivier Robert To: freebsd-fs@freebsd.org Message-ID: <20071128093919.GA28019@keltia.freenix.fr> References: <20071128091336.GA95214@gw.reifenberger.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20071128091336.GA95214@gw.reifenberger.com> X-Operating-System: MacOS X / Macbook Pro - FreeBSD 6.2 / Dell D820 SMP User-Agent: Mutt/1.5.15 (2007-04-06) Subject: Re: Recommendated disk layout for ZFS 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: Wed, 28 Nov 2007 09:55:27 -0000 According to Michael Reifenberger: > having 6 Disks I have some possibillities for the disk layout: > > - all 6 disks in raidz > - 2 * 3 disk in raidz > - 3 * 2 disk in raid1 You forgot : - all 6 disks in raidz2 (4 used for storage, 2 parity) > What would be the preferred layout from an performance POV? Read or write performance? Write performance is probably better with raid1, knowing that the three mirrors will be stripped together automatically. A better compromise could be, 5 disks in raidz(2), and one spare disk. You also must consider how much space you want, all configurations have different usable disk space profiles. a. 5 usable disks (83%) b. 4 usable disks (66%) c. 3 usable disks (50%) d. 4 usable disks (66%) e. 4 or 3 usable disks and one spare (66 - 50%) > Has anyone allready done a throughput comparison of the different layouts? Haven't seen one yet. -- Ollivier ROBERT -=- FreeBSD: The Power to Serve! -=- roberto@keltia.freenix.fr Darwin sidhe.keltia.net Version 8.10.1: Wed May 23 16:33:00 PDT 2007 i386