From owner-freebsd-questions@FreeBSD.ORG Wed Jul 23 11:12:02 2014 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 56E73ED3 for ; Wed, 23 Jul 2014 11:12:02 +0000 (UTC) Received: from alogt.com (alogt.com [69.36.191.58]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 26EAA2E57 for ; Wed, 23 Jul 2014 11:12:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=alogt.com; s=default; h=Content-Transfer-Encoding:Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Subject:Cc:To:From:Date; bh=C7Hu/Eivs/QeR7FU42YoEn1QiSm0mksY7K+XpBjeC2U=; b=cWv+ouJyuwDFbOIDeNKTuOlXG0XbzOK6dD0yPM0HkG0IfPQ1Syz+Vibtl8pPfKJl6LmErb8R1JBrJoIi+apxRd+4hym11GP2VWJNEkj1xZ993XEvGEKW/C8kMJrURdlzpyrcix3AfbTpxj9aAL2IbJwm90cxGoEh5cLf3CKpegs=; Received: from [39.251.220.217] (port=41435 helo=X220.alogt.com) by sl-508-2.slc.westdc.net with esmtpsa (SSLv3:DHE-RSA-AES128-SHA:128) (Exim 4.82) (envelope-from ) id 1X9tj3-004O81-K4; Wed, 23 Jul 2014 04:24:46 -0600 Date: Wed, 23 Jul 2014 18:24:37 +0800 From: Erich Dollansky To: Arthur Chance Subject: Re: How much swap space for a 32 GB RAM system? Message-ID: <20140723182437.76a21d55@X220.alogt.com> In-Reply-To: <53CF6820.7080103@qeng-ho.org> References: <53CE8BB8.7030303@qeng-ho.org> <20140722203928.6993a78d@gumby.homeunix.com> <53CF6820.7080103@qeng-ho.org> X-Mailer: Claws Mail 3.10.1 (GTK+ 2.24.22; amd64-portbld-freebsd10.0) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - sl-508-2.slc.westdc.net X-AntiAbuse: Original Domain - freebsd.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - alogt.com X-Get-Message-Sender-Via: sl-508-2.slc.westdc.net: authenticated_id: erichsfreebsdlist@alogt.com X-Source: X-Source-Args: X-Source-Dir: Cc: RW , freebsd-questions@freebsd.org X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 23 Jul 2014 11:12:02 -0000 Hi, On Wed, 23 Jul 2014 08:45:36 +0100 Arthur Chance wrote: > On 23/07/2014 03:32, Warren Block wrote: > > On Tue, 22 Jul 2014, RW wrote: > > > >> On Tue, 22 Jul 2014 10:24:13 -0600 (MDT) > >> Warren Block wrote: > >> > >>> On Tue, 22 Jul 2014, Arthur Chance wrote: > >>> > >>>> I'm getting a new machine with 32 GB of memory. The old "twice > >>>> physical memory" sizing seems ridiculous, so how big should I > >>>> make swap? Do I even need swap with this much memory? > >>> as you have heard a lot of opinions and also found tuning, allow me to share my experience. I am still use swap to be size double of the RAM. The reason is simple. Disk space is cheap. You do not need a fast device for swap if you have a lot of memory but swap makes FreeBSD survive if memory becomes a problem. It also helps you giving you time to fix things manually while the machine is running. On the other side, I have had a single occasion within the last some 5 years in which a big swap helped me. So, it is really rare that you will need a large swap partition. Erich