From owner-freebsd-performance@FreeBSD.ORG Wed Apr 30 14:50:47 2003 Return-Path: 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 D849437B401 for ; Wed, 30 Apr 2003 14:50:47 -0700 (PDT) Received: from mail.ubergeeks.com (lorax.ubergeeks.com [209.145.65.55]) by mx1.FreeBSD.org (Postfix) with ESMTP id CEDC943F85 for ; Wed, 30 Apr 2003 14:50:44 -0700 (PDT) (envelope-from adrian+freebsd-perf@ubergeeks.com) Received: from mail.ubergeeks.com (localhost [127.0.0.1]) by mail.ubergeeks.com (8.12.8p1/8.12.8) with ESMTP id h3ULoh0D060249; Wed, 30 Apr 2003 17:50:43 -0400 (EDT) (envelope-from adrian+freebsd-perf@ubergeeks.com) Received: from localhost (adrian@localhost)h3ULohoW060246; Wed, 30 Apr 2003 17:50:43 -0400 (EDT) (envelope-from adrian+freebsd-perf@ubergeeks.com) X-Authentication-Warning: lorax.ubergeeks.com: adrian owned process doing -bs Date: Wed, 30 Apr 2003 17:50:43 -0400 (EDT) From: Adrian Filipi-Martin Sender: adrian@ubergeeks.com To: Michael Nottebrock In-Reply-To: <200304282314.22236.michaelnottebrock@gmx.net> Message-ID: <20030430174616.E59039@lorax.ubergeeks.com> References: <200304281054.48976.ryba@kompakt.pl> <200304282314.22236.michaelnottebrock@gmx.net> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII cc: freebsd-performance@freebsd.org Subject: Re: SWAP size X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 30 Apr 2003 21:50:48 -0000 On Mon, 28 Apr 2003, Michael Nottebrock wrote: > On Monday 28 April 2003 10:54, Piotr Rybicki wrote: > > Hi everyone. > > > > In man tuning(7) we read, that swap size should be about 2x main memmory > > size. Why swap size should be so big? Isn't swap size equal to main memmory > > size enough? > > IMHO the swapsize=2x phys. mem size has always been just a rule of thumb. You > need as much swap as you need (doh). But so far, the memory requirements of > software have pretty much grown proportionally with the availibility / > affordability of bigger sticks of memory and thus the rule of thumb still > makes sense. YMMV. > > -- > Regards, > Michael Nottebrock It used to mean something. 1x for swapping (whole processes) and 1x for paging (just pages of a process). Each portion was used for exactly one purpose. This is no longer a valid reason though. IIRC, it is because FreeBSD has a unified buffer cache. I don't know if there are any other reasons for 2x. I don't bothe with more than 1x personally, if that much. Swap space is really there for emergencies only IMHO. Adrian -- [ adrian@ubergeeks.com ]