From owner-freebsd-fs Thu Nov 4 15:46:40 1999 Delivered-To: freebsd-fs@freebsd.org Received: from caspian.plutotech.com (caspian.plutotech.com [206.168.67.80]) by hub.freebsd.org (Postfix) with ESMTP id 325DD1518D for ; Thu, 4 Nov 1999 15:46:36 -0800 (PST) (envelope-from gibbs@caspian.plutotech.com) Received: from caspian.plutotech.com (localhost [127.0.0.1]) by caspian.plutotech.com (8.9.3/8.9.1) with ESMTP id PAA05113; Thu, 4 Nov 1999 15:45:26 -0700 (MST) (envelope-from gibbs@caspian.plutotech.com) Message-Id: <199911042245.PAA05113@caspian.plutotech.com> X-Mailer: exmh version 2.1.0 09/18/1999 To: Kelly Yancey Cc: Greg Lehey , Bernd Walter , Mattias Pantzare , freebsd-fs@FreeBSD.ORG Subject: Re: feature list journalled fs In-reply-to: Your message of "Thu, 04 Nov 1999 18:33:24 EST." Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Thu, 04 Nov 1999 15:45:26 -0700 From: "Justin T. Gibbs" Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org >On Thu, 4 Nov 1999, Greg Lehey wrote: > >> >> That's for writing. When throughput becomes the limit, the write >> throughput of RAID-4 is limited to about 2 / n of the write throughput >> of RAID-5. On reading (randomly), it's (n - 1) / n. >> > > I think that it has been significantly proven that RAID 4 is not very >userful, and I regret bringing it up...sometimes the mind wonders :). It all depends on your application. If you are dealing with a data set composed of large, fixed sized entries, RAID 3 or 4 (they are almost identical) will always outperform RAID5. -- Justin To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message