From owner-freebsd-stable@FreeBSD.ORG Tue Nov 9 18:09:00 2004 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 63BA816A4CE for ; Tue, 9 Nov 2004 18:09:00 +0000 (GMT) Received: from pi.codefab.com (pi.codefab.com [199.103.21.227]) by mx1.FreeBSD.org (Postfix) with ESMTP id 0282E43D41 for ; Tue, 9 Nov 2004 18:09:00 +0000 (GMT) (envelope-from cswiger@mac.com) Received: from [192.168.1.250] (pool-68-161-115-118.ny325.east.verizon.net [68.161.115.118]) by pi.codefab.com (8.12.11/8.12.11) with ESMTP id iA9I8dOS075492 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 9 Nov 2004 13:08:51 -0500 (EST) Message-ID: <4191078B.1040807@mac.com> Date: Tue, 09 Nov 2004 13:08:11 -0500 From: Chuck Swiger Organization: The Courts of Chaos User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.3) Gecko/20040910 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Vivek Khera References: <0B0B1841-31CC-11D9-8097-003065ABFD92@mac.com> <968F78D2-326F-11D9-9E53-000A9578CFCC@khera.org> In-Reply-To: <968F78D2-326F-11D9-9E53-000A9578CFCC@khera.org> X-Enigmail-Version: 0.86.1.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, hits=-4.1 required=5.5 tests=AWL,BAYES_00 autolearn=ham version=2.64 X-Spam-Checker-Version: SpamAssassin 2.64 (2004-01-11) on pi.codefab.com cc: freebsd-stable@freebsd.org Subject: Re: Filesystem buffer size X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 09 Nov 2004 18:09:00 -0000 Vivek Khera wrote: > On Nov 8, 2004, at 4:20 PM, Charles Swiger wrote: >> So long as the system has enough memory available for the working sets >> of the processes being run, FreeBSD will use the rest of the memory >> for caching stuff from the filesystem without needing any special tuning. > > Are you sure of this? No. :-) However, I'm willing to count not just the actual disk buffer cache itself, but process-level caching of files. The OP didn't mention what kind of server application he was using, but things like squid and apache will buffer files into RAM (ie, the process' address space). I am not as sure about things like NFS or Samba/CIFS. > The disk buffer cache from what I have learned is > maxed out at 200Mb, which is a small fraction of a 4GB RAM box. OK. If you've got many hundreds of MBs worth to deal with, perhaps using md(4) would be a better idea. -- -Chuck