From owner-freebsd-performance@FreeBSD.ORG Sat Aug 12 15:41:45 2006 Return-Path: X-Original-To: freebsd-performance@freebsd.org Delivered-To: freebsd-performance@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 1F1BA16A4DF for ; Sat, 12 Aug 2006 15:41:45 +0000 (UTC) (envelope-from rwatson@FreeBSD.org) Received: from cyrus.watson.org (cyrus.watson.org [209.31.154.42]) by mx1.FreeBSD.org (Postfix) with ESMTP id DBD9243D64 for ; Sat, 12 Aug 2006 15:41:43 +0000 (GMT) (envelope-from rwatson@FreeBSD.org) Received: from fledge.watson.org (fledge.watson.org [209.31.154.41]) by cyrus.watson.org (Postfix) with ESMTP id 1BAC446C8D; Sat, 12 Aug 2006 11:41:43 -0400 (EDT) Date: Sat, 12 Aug 2006 16:41:43 +0100 (BST) From: Robert Watson X-X-Sender: robert@fledge.watson.org To: Nikolas Britton In-Reply-To: Message-ID: <20060812164039.T45647@fledge.watson.org> References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: freebsd-performance@freebsd.org Subject: Re: VFS sysctl tuning X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 12 Aug 2006 15:41:45 -0000 On Sat, 12 Aug 2006, Nikolas Britton wrote: > After reading man tuning it said to change vfs.hirunningspace to a larger > value. What should I set it to? > > My RAID controller, an Areca ARC-1220, has a 256MB cache and each disk has > 16MB of cache. > > What other vfs.* sysctls can I change? The default settings are "reasonable" for many common workloads. Further tuning generally should be done in the context of a specific workload, since tuning generally means trading off one type of performance or functionality for another. Only by knowing the workload can we talk about how to trade off what you need, and what you don't. Robert N M Watson Computer Laboratory University of Cambridge