From owner-cvs-src@FreeBSD.ORG Fri Aug 20 19:35:52 2004 Return-Path: Delivered-To: cvs-src@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id EDAEB16A4CE; Fri, 20 Aug 2004 19:35:51 +0000 (GMT) Received: from darkness.comp.waw.pl (darkness.comp.waw.pl [195.117.238.236]) by mx1.FreeBSD.org (Postfix) with ESMTP id 6C92043D2D; Fri, 20 Aug 2004 19:35:50 +0000 (GMT) (envelope-from pjd@darkness.comp.waw.pl) Received: by darkness.comp.waw.pl (Postfix, from userid 1009) id 50401ACAFE; Fri, 20 Aug 2004 21:35:47 +0200 (CEST) Date: Fri, 20 Aug 2004 21:35:47 +0200 From: Pawel Jakub Dawidek To: Greg 'groggy' Lehey Message-ID: <20040820193547.GZ30151@darkness.comp.waw.pl> References: <20040817132740.GA32139@freebie.xs4all.nl> <41449.1092750244@critter.freebsd.dk> <200408161043.i7GAhfXs079045@repoman.freebsd.org> <20040817004407.GA81257@wantadilla.lemis.com> <20040817074633.GO30151@darkness.comp.waw.pl> <20040817112900.GA31635@freebie.xs4all.nl> <20040817124020.GK88156@wantadilla.lemis.com> <20040817131612.GT30151@darkness.comp.waw.pl> <20040819024359.GA85432@wantadilla.lemis.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="2bJ57vwr75KGnr5s" Content-Disposition: inline In-Reply-To: <20040819024359.GA85432@wantadilla.lemis.com> User-Agent: Mutt/1.4.2i X-PGP-Key-URL: http://people.freebsd.org/~pjd/pjd.asc X-OS: FreeBSD 5.2.1-RC2 i386 cc: src-committers@FreeBSD.ORG cc: cvs-src@FreeBSD.ORG cc: cvs-all@FreeBSD.ORG cc: Poul-Henning Kamp cc: Wilko Bulte cc: freebsd-performance@freebsd.org Subject: Re: RAID-3? (was: cvs commit: src MAINTAINERS) X-BeenThere: cvs-src@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: CVS commit messages for the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 20 Aug 2004 19:35:52 -0000 --2bJ57vwr75KGnr5s Content-Type: text/plain; charset=iso-8859-2 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Aug 19, 2004 at 12:13:59PM +0930, Greg 'groggy' Lehey wrote: +> On Tuesday, 17 August 2004 at 15:16:12 +0200, Pawel Jakub Dawidek wrote: +> > On Tue, Aug 17, 2004 at 10:10:20PM +0930, Greg 'groggy' Lehey wrote: +> > +> On the contrary. RAID-3 requires byte-level striping, which is +> > +> ridiculous on the hardware that FreeBSD supports. [...] +> > Want to compare performance with vinum's RAID5?:) +>=20 +> Feel free. But do it with more than a single process accessing the +> disks. Tests were done using this HW: CPU: Pentium II/Pentium II Xeon/Celeron (534.55-MHz 686-class CPU) Origin =3D "GenuineIntel" Id =3D 0x665 Stepping =3D 5 Features=3D0x183fbff real memory =3D 67108864 (64 MB) avail memory =3D 60256256 (57 MB) MPTable: FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs [...] iir0: mem 0xd8100000-0xd8103fff irq 17 at devic= e 13.0 on pci0 [...] da0 at iir0 bus 2 target 0 lun 0 da0: Fixed Direct Access SCSI-2 device=20 da0: Tagged Queueing Enabled da0: 8675MB (17767890 512 byte sectors: 255H 63S/T 1106C) da1 at iir0 bus 2 target 1 lun 0 da1: Fixed Direct Access SCSI-2 device=20 da1: Tagged Queueing Enabled da1: 8675MB (17767890 512 byte sectors: 255H 63S/T 1106C) da2 at iir0 bus 2 target 2 lun 0 da2: Fixed Direct Access SCSI-2 device=20 da2: Tagged Queueing Enabled da2: 8675MB (17767890 512 byte sectors: 255H 63S/T 1106C) The software you can find under /usr/src/tools/tools/raidtest/ in HEAD branch. Test has been done for 10000 random requests (offset, size and operation type was random). RAID3: Number of Bytes per Requests per Operations processes second second ---------------------------------------------------------------------- READ 3 6329500 95 READ 15 8981047 135 READ 100 10719314 161 WRITE 3 5073263 76 WRITE 15 7467387 112 WRITE 100 8631136 129 READ/WRITE 3 6041795 90 READ/WRITE 15 8104847 121 READ/WRITE 100 9494250 142 RAID5: Number of Bytes per Requests per Operations processes second second ---------------------------------------------------------------------- READ 3 6041795 90 READ 15 14768833 222 READ 100 19546985 294 WRITE 3 3479568 52 WRITE 15 5403231 81 WRITE 100 6211191 93 READ/WRITE 3 4521071 68 READ/WRITE 15 7911875 119 READ/WRITE 100 9360528 140 As you can see RAID5 is only faster in READ tests for 15 and 100 processes working in parallel. As I can see, RAID3 is faster in all the rest tests. Of course you are welcome to try by yourself. Anyway, if I can ask for something. Think twice before calling something ridiculous without understanding. PS. I wonder about read optimization, so parity component can be also used for reading in round-robin fashion... --=20 Pawel Jakub Dawidek http://www.FreeBSD.org pjd@FreeBSD.org http://garage.freebsd.pl FreeBSD committer Am I Evil? Yes, I Am! --2bJ57vwr75KGnr5s Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (FreeBSD) iD8DBQFBJlKTForvXbEpPzQRAsw9AJ4iJ0Hhuuxnjz31dXV+ofw53x1SdACg8jfa f510URPthDkHrRA/rpIUwX0= =QqXC -----END PGP SIGNATURE----- --2bJ57vwr75KGnr5s--