From owner-freebsd-geom@FreeBSD.ORG Fri Sep 21 17:06:47 2007 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 142BB16A419 for ; Fri, 21 Sep 2007 17:06:47 +0000 (UTC) (envelope-from pjd@garage.freebsd.pl) Received: from mail.garage.freebsd.pl (arm132.internetdsl.tpnet.pl [83.17.198.132]) by mx1.freebsd.org (Postfix) with ESMTP id 67D0F13C45D for ; Fri, 21 Sep 2007 17:06:46 +0000 (UTC) (envelope-from pjd@garage.freebsd.pl) Received: by mail.garage.freebsd.pl (Postfix, from userid 65534) id 1F4CF45E90; Fri, 21 Sep 2007 19:06:45 +0200 (CEST) Received: from localhost (154.81.datacomsa.pl [195.34.81.154]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.garage.freebsd.pl (Postfix) with ESMTP id 7AAE3456AB; Fri, 21 Sep 2007 19:06:35 +0200 (CEST) Date: Fri, 21 Sep 2007 19:05:07 +0200 From: Pawel Jakub Dawidek To: ?????? ??????? Message-ID: <20070921170506.GB9445@garage.freebsd.pl> References: <20070921143318.GC5690@garage.freebsd.pl> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="tjCHc7DPkfUGtrlw" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.3i X-PGP-Key-URL: http://people.freebsd.org/~pjd/pjd.asc X-OS: FreeBSD 7.0-CURRENT i386 X-Spam-Checker-Version: SpamAssassin 3.0.4 (2005-06-05) on mail.garage.freebsd.pl X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=BAYES_00 autolearn=ham version=3.0.4 Cc: Pawel Jakub Dawidek Subject: Re: raidtest for zfs 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: Fri, 21 Sep 2007 17:06:47 -0000 --tjCHc7DPkfUGtrlw Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Sep 21, 2007 at 08:33:47PM +0400, ?????? ??????? wrote: > > > How to run raidtest ( > > > http://www.freebsdsoftware.org/benchmarks/raidtest.html ) on zfs? > > > > > > diskinfo dos'n work. > > > > raidtest is for block device testing. If you want to test ZFS with it, > > you need to create ZVOL with 'zfs create -V' command, eg. > > > > # zpool create tank raidz da{0,1,2,3,4} > > # zfs create -V 100g tank/vol > > # diskinfo -v /dev/zvol/tank/vol >=20 >=20 >=20 > I get strange and fantastic results: >=20 > > raidtest genfile -s 209715200 -S 512 -n 50000 -r -f > File raidtest.data generated. > Number of READ requests: 50000. > Number of WRITE requests: 0. > Number of bytes to transmit: 3279956992. >=20 > > raidtest test -d /dev/zvol/tank/vol -n 10 > Read 50000 requests from raidtest.data. > Number of READ requests: 50000. > Number of WRITE requests: 0. > Number of bytes to transmit: 3279956992. > Number of processes: 10. > Bytes per second: 245146813 > Requests per second: 3737 > ^^^^^ - too big! >=20 > > raidtest genfile -s 209715200 -S 512 -n 50000 -f > File raidtest.data generated. > Number of READ requests: 25046. > Number of WRITE requests: 24954. > Number of bytes to transmit: 3311506944. >=20 > > raidtest test -d /dev/zvol/tank/vol -n 10 > Read 50000 requests from raidtest.data. > Number of READ requests: 25046. > Number of WRITE requests: 24954. > Number of bytes to transmit: 3311506944. > Number of processes: 10. > Bytes per second: 195043585 > Requests per second: 2944 > ^^^^^ - too big! >=20 >=20 > The real results is: >=20 > > raidtest test -d /dev/raid3/g3 -n 10 > Read 50000 requests from raidtest.data. > Number of READ requests: 50000. > Number of WRITE requests: 0. > Number of bytes to transmit: 3316146176. > Number of processes: 10. > Bytes per second: 11398078 > Requests per second: 171 >=20 > What is wrong? >=20 > How to run raidtest correctly on /dev/zvol/tank/vol ? Ok. Here it how it works. ZFS has this COW model. It doesn't preallocate space. When you read blocks you never written, it won't touch the disks, but will just return zeros. To properly test read performance, you first need to write, so you should first run raidtest with -w flag, then zpool export/import your pool to remove cache and then retest with or without -r flag. --=20 Pawel Jakub Dawidek http://www.wheel.pl pjd@FreeBSD.org http://www.FreeBSD.org FreeBSD committer Am I Evil? Yes, I Am! --tjCHc7DPkfUGtrlw Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4 (FreeBSD) iD8DBQFG8/nCForvXbEpPzQRAp9iAJ9iGXN7TtJRVuYhF/g8Sfr9HHxDkQCg1Qav 4y3k9cf5w4OQ3UnuX0fcxN0= =a6vi -----END PGP SIGNATURE----- --tjCHc7DPkfUGtrlw--