Date: Sat, 21 Aug 2004 10:33:55 +0200 From: Pawel Jakub Dawidek <pjd@FreeBSD.org> To: Greg 'groggy' Lehey <grog@FreeBSD.org> Cc: freebsd-performance@freebsd.org Subject: Re: RAID-3? (was: cvs commit: src MAINTAINERS) Message-ID: <20040821083355.GD30151@darkness.comp.waw.pl> In-Reply-To: <20040821082838.GF92256@wantadilla.lemis.com> References: <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> <20040820193547.GZ30151@darkness.comp.waw.pl> <20040821082838.GF92256@wantadilla.lemis.com>
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--Wl2tksQRuA3a9k2N Content-Type: text/plain; charset=iso-8859-2 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sat, Aug 21, 2004 at 05:58:38PM +0930, Greg 'groggy' Lehey wrote: +> So these are two disks + parity, right? That's not exactly a typical +> setup. Yes. +> > RAID5: +>=20 +> What was the RAID-5 stripe size? 256kB. +> > As you can see RAID5 is only faster in READ tests for 15 and 100 proce= sses +> > working in parallel. As I can see, RAID3 is faster in all the rest tes= ts. +>=20 +> I don't really see enough to convince me either way. If you use small +> RAID-5 stripes, then yes, it's possible to get better performance from +> RAID-3. I'd also suggest that your figures would look very different +> with five or nine disks. It would also be interested to see the +> results of rawio on these configurations, and also the relative +> performance of a single disk. Ok, wait for my reading optimization results:) --=20 Pawel Jakub Dawidek http://www.FreeBSD.org pjd@FreeBSD.org http://garage.freebsd.pl FreeBSD committer Am I Evil? Yes, I Am! --Wl2tksQRuA3a9k2N Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (FreeBSD) iD8DBQFBJwjzForvXbEpPzQRAk2uAKDzWlM4i7djtP90OnbQjz9d5AYj0gCgrVrH z7czl5tbnyf76yaA8a9cP/8= =k0SP -----END PGP SIGNATURE----- --Wl2tksQRuA3a9k2N--
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