From owner-freebsd-hackers Thu Jun 18 19:04:17 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id TAA27385 for freebsd-hackers-outgoing; Thu, 18 Jun 1998 19:04:17 -0700 (PDT) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from sasami.jurai.net (winter@sasami.jurai.net [207.153.65.3]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id TAA27360 for ; Thu, 18 Jun 1998 19:04:11 -0700 (PDT) (envelope-from winter@jurai.net) Received: from localhost (winter@localhost) by sasami.jurai.net (8.8.8/8.8.7) with SMTP id WAA00596; Thu, 18 Jun 1998 22:03:51 -0400 (EDT) Date: Thu, 18 Jun 1998 22:03:50 -0400 (EDT) From: "Matthew N. Dodd" To: IBS / Andre Oppermann cc: spork , hackers@FreeBSD.ORG Subject: Re: Disk Cache In-Reply-To: <358998E2.32A7AF2F@pipeline.ch> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Fri, 19 Jun 1998, IBS / Andre Oppermann wrote: > You better spend the money on 'real' RAM, FreeBSD does a better job > managing cache then every caching controller because FreeBSD 'knows' > what it needs next, the caching simply reads ahead. For read caching this statement is true. > > The kernel has no way of knowing that some things are already cached out > > beyond the SCSI card, so I assume it would cache something that's already > > cached, right? How do you work around that? Is there some way of telling > > There's only one 'workaround': disable caching in FreeBSD with the > "sync" > mount option. Now you are talking about write caching which is a completly different matter. Write caching should be a big win as it allows more efficient use of your drives (by reducing seeks when your data has a high locality of reference.) /* Matthew N. Dodd | A memory retaining a love you had for life winter@jurai.net | As cruel as it seems nothing ever seems to http://www.jurai.net/~winter | go right - FLA M 3.1:53 */ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message