From owner-freebsd-questions@FreeBSD.ORG  Mon Jul  5 23:27:53 2004
Return-Path: <owner-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 5FD4B16A4CE
	for <freebsd-questions@freebsd.org>;
	Mon,  5 Jul 2004 23:27:53 +0000 (GMT)
Received: from internet.potentialtech.com (h-66-167-251-6.phlapafg.covad.net
	[66.167.251.6])	by mx1.FreeBSD.org (Postfix) with ESMTP id 0928143D60
	for <freebsd-questions@freebsd.org>;
	Mon,  5 Jul 2004 23:27:51 +0000 (GMT)
	(envelope-from wmoran@potentialtech.com)
Received: from working.potentialtech.com
	(pa-plum-cmts1e-68-68-113-64.pittpa.adelphia.net [68.68.113.64])
	by internet.potentialtech.com (Postfix) with ESMTP id 3D69569A39;
	Mon,  5 Jul 2004 19:27:50 -0400 (EDT)
Date: Mon, 5 Jul 2004 19:27:48 -0400
From: Bill Moran <wmoran@potentialtech.com>
To: Lists <lists@perespim.net>
Message-Id: <20040705192748.28d50eb3.wmoran@potentialtech.com>
In-Reply-To: <71704ff3727060e5144ffddc6ee8daed@159.148.60.10>
References: <71704ff3727060e5144ffddc6ee8daed@159.148.60.10>
Organization: Potential Technologies
X-Mailer: Sylpheed version 0.9.12 (GTK+ 1.2.10; i386-portbld-freebsd4.9)
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
cc: freebsd-questions@freebsd.org
Subject: Re: Swap size
X-BeenThere: freebsd-questions@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: User questions <freebsd-questions.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>,
	<mailto:freebsd-questions-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-questions>
List-Post: <mailto:freebsd-questions@freebsd.org>
List-Help: <mailto:freebsd-questions-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>,
	<mailto:freebsd-questions-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 05 Jul 2004 23:27:53 -0000

Lists <lists@perespim.net> wrote:
> Hello all,
> 
>     What swap size should i use having 768 Mb of memory?
>     I've heard something about preformance degradation if
>     swap size is bellow 2x of ram...

Other's have pointed out that you don't _need_ swap space.  If you have
enough RAM, you can operate without it.

However, if you need to do kernel core dumps (in the even you run into kernel
panic problems) you will need at least as much swap space as you have RAM,
plus a little.

Additionally, if your machine ever does start to swap, FreeBSD's VM code
_is_ optimized on the assumption that you have 2x your RAM in swap.  If
the machine starts to swap, you will get the best performance under all
loads (including _heavy_ swapping) if you have 2x RAM in swap.

However, FreeBSD still performs nicely with less swap than that.

-- 
Bill Moran
Potential Technologies
http://www.potentialtech.com