From owner-freebsd-stable@FreeBSD.ORG Tue Apr 11 09:28:25 2006 Return-Path: X-Original-To: freebsd-stable@freebsd.org 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 4A8F216A400 for ; Tue, 11 Apr 2006 09:28:25 +0000 (UTC) (envelope-from peterjeremy@optushome.com.au) Received: from mail18.syd.optusnet.com.au (mail18.syd.optusnet.com.au [211.29.132.199]) by mx1.FreeBSD.org (Postfix) with ESMTP id 4671E43D46 for ; Tue, 11 Apr 2006 09:28:24 +0000 (GMT) (envelope-from peterjeremy@optushome.com.au) Received: from turion.vk2pj.dyndns.org (c220-239-19-236.belrs4.nsw.optusnet.com.au [220.239.19.236]) by mail18.syd.optusnet.com.au (8.12.11/8.12.11) with ESMTP id k3B9SLq4009369 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=NO); Tue, 11 Apr 2006 19:28:21 +1000 Received: from turion.vk2pj.dyndns.org (localhost.vk2pj.dyndns.org [127.0.0.1]) by turion.vk2pj.dyndns.org (8.13.4/8.13.4) with ESMTP id k3B9SKgZ001157; Tue, 11 Apr 2006 19:28:20 +1000 (EST) (envelope-from peter@turion.vk2pj.dyndns.org) Received: (from peter@localhost) by turion.vk2pj.dyndns.org (8.13.4/8.13.4/Submit) id k3B9SKj9001156; Tue, 11 Apr 2006 19:28:20 +1000 (EST) (envelope-from peter) Date: Tue, 11 Apr 2006 19:28:19 +1000 From: Peter Jeremy To: Pete Slagle Message-ID: <20060411092819.GA707@turion.vk2pj.dyndns.org> References: <1dbad3150604100913hff9fc4dsb125ea541675f992@mail.gmail.com> <20060410161713.GA48094@xor.obsecurity.org> <200604111048.09905.doconnor@gsoft.com.au> <443B0A51.8040206@voidcaptain.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <443B0A51.8040206@voidcaptain.com> X-PGP-Key: http://members.optusnet.com.au/peterjeremy/pubkey.asc User-Agent: Mutt/1.5.11 Cc: freebsd-stable@freebsd.org Subject: Re: Maximum Swapsize X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 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, 11 Apr 2006 09:28:25 -0000 On Mon, 2006-Apr-10 18:45:53 -0700, Pete Slagle wrote: >When you have very limited physical RAM you need a lot of swap space. >When you have more than enough RAM you don't need any swap space at all. >For a given set of applications, as RAM increases you need less swap >space, not more. And vice versa. The key point here is "for a given set of applications". Whilst I could (in theory) attach 1GB swap to my 4MB 486 and run openoffice and mozilla, in practice, the performance would rapidly discourage me. In reality, you need enough RAM to hold your application's working set (plus kernel and FS overheads) and enough swap to hold the rest of the applications writable virtual space. The 2:1 is a reasonably general rule of thumb because if there's not enough RAM, people either add more RAM or don't run as many applications. That said, I run about 6:1 on my desktop at work because I tend to leave lots of windows lying around idle for long periods. -- Peter Jeremy