From owner-freebsd-geom@FreeBSD.ORG Sun Jun 28 08:35:20 2009 Return-Path: Delivered-To: freebsd-geom@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id EBD1E1065675 for ; Sun, 28 Jun 2009 08:35:20 +0000 (UTC) (envelope-from andrew@modulus.org) Received: from email.octopus.com.au (email.octopus.com.au [122.100.2.232]) by mx1.freebsd.org (Postfix) with ESMTP id AC03B8FC0A for ; Sun, 28 Jun 2009 08:35:20 +0000 (UTC) (envelope-from andrew@modulus.org) Received: by email.octopus.com.au (Postfix, from userid 1002) id 6D34E172D8; Sun, 28 Jun 2009 18:16:49 +1000 (EST) X-Spam-Checker-Version: SpamAssassin 3.2.3 (2007-08-08) on email.octopus.com.au X-Spam-Level: X-Spam-Status: No, score=-0.3 required=10.0 tests=ALL_TRUSTED,DNS_FROM_DOB, RCVD_IN_DOB autolearn=no version=3.2.3 Received: from [10.20.30.102] (60.218.233.220.static.exetel.com.au [220.233.218.60]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: admin@email.octopus.com.au) by email.octopus.com.au (Postfix) with ESMTP id 0DC3917258; Sun, 28 Jun 2009 18:16:41 +1000 (EST) Message-ID: <4A4725FA.80505@modulus.org> Date: Sun, 28 Jun 2009 18:12:42 +1000 From: Andrew Snow User-Agent: Thunderbird 2.0.0.6 (X11/20070926) MIME-Version: 1.0 To: Dan Naumov References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-fs@freebsd.org, freebsd-geom@freebsd.org Subject: Re: read/write benchmarking: UFS2 vs ZFS vs EXT3 vs ZFS RAIDZ vs Linux MDRAID X-BeenThere: freebsd-geom@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: GEOM-specific discussions and implementations List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 28 Jun 2009 08:35:21 -0000 > Contiguous Write Performance: > http://virtual.tehinterweb.net/livejournal/2009-06-22_zfs_diskperf/zfs-diskperf-contig-write.png What confuses me about these results is that the '5 disk' performance was barely higher than the 'single disk' performance. All figures are also lower than I get from a single modern SATA disk. My own testing with dd from /dev/zero with FreeBSD ZFS an Intel ICH10 chipset motherboard with Core2duo 2.66ghz showed RAIDZ performance scaling linearly with number of disks: What Write Read -------------------------------- 7 disk RAIDZ2 220 305 6 disk RAIDZ2 173 260 5 disk RAIDZ2 120 213 Only the on-board controllers were used, with Seagate disks of around 250GB capacity. System had 8GB RAM. These results are so different in absolute terms to your results that I don't know how to interpret your set. - Andrew