From owner-freebsd-questions@FreeBSD.ORG Tue Nov 1 16:00:19 2005 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id C183916A41F for ; Tue, 1 Nov 2005 16:00:19 +0000 (GMT) (envelope-from jerrymc@clunix.cl.msu.edu) Received: from clunix.cl.msu.edu (clunix.cl.msu.edu [35.9.2.10]) by mx1.FreeBSD.org (Postfix) with ESMTP id 6A18D43D49 for ; Tue, 1 Nov 2005 16:00:19 +0000 (GMT) (envelope-from jerrymc@clunix.cl.msu.edu) Received: from clunix.cl.msu.edu (localhost [127.0.0.1]) by clunix.cl.msu.edu (8.12.10+Sun/8.12.2) with ESMTP id jA1G0I38022145; Tue, 1 Nov 2005 11:00:18 -0500 (EST) Received: (from jerrymc@localhost) by clunix.cl.msu.edu (8.12.10+Sun/8.12.2/Submit) id jA1G0I3T022144; Tue, 1 Nov 2005 11:00:18 -0500 (EST) From: Jerry McAllister Message-Id: <200511011600.jA1G0I3T022144@clunix.cl.msu.edu> To: mailing-lists@msdi.ca (Ian Lord) Date: Tue, 1 Nov 2005 11:00:18 -0500 (EST) In-Reply-To: <6.2.3.4.2.20051101094812.030e2d20@pop.msdi.ca> X-Mailer: ELM [version 2.5 PL7] MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: freebsd-questions@freebsd.org Subject: Re: Swap space X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 01 Nov 2005 16:00:19 -0000 > > Hi, > > I just bought 4 servers with 4 gigs of ram, the documentation > proposes to use 2 to 3 times the amount of ram for swap... I don't > think 12 gigs of swap would be useful lol, but do I really need to > put 4 gigs of ram. (It might be useful for kernel dump but...) > > What do you guys do with swap space in this scenario ? Swap space gets used for at least three things, swapping, paging and kernel crash dump space. If you are not concerned about dump space, then the rest of the decision depends a lot on the size and number of processes you expect to be running at any given time. Generally, for smaller memory sizes, swap space, via paging gives you a larger virtual space to run in. But, it looks like you may by trying to make it so everything gets to stay in memory and never have any of it paged out, much less swapped out. For our systems that have plenty of memory, I tend to use about 1 1/2 times memory for the size of swap - plenty of memory meaning as much as it can address or at least more than enough to cover all simultaneous processes. Remember that a lot of utilities and daemons fork off new processes for each incident they encounter rather than queueing stuff for the main process to handle. They sort of use it for poor mans queueing. ////jerry > > Thanks > _______________________________________________ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.org" >