From owner-freebsd-questions@FreeBSD.ORG Fri Aug 17 15:07:20 2007 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id DF97B16A41B for ; Fri, 17 Aug 2007 15:07:20 +0000 (UTC) (envelope-from greenwood.andy@gmail.com) Received: from agreenftp.no-ip.com (75-137-118-150.dhcp.gnvl.sc.charter.com [75.137.118.150]) by mx1.freebsd.org (Postfix) with ESMTP id A922613C467 for ; Fri, 17 Aug 2007 15:07:20 +0000 (UTC) (envelope-from greenwood.andy@gmail.com) Received: from localhost (localhost [127.0.0.1]) by agreenftp.no-ip.com (Postfix) with ESMTP id 3673D39843; Fri, 17 Aug 2007 11:07:20 -0400 (EDT) X-Virus-Scanned: amavisd-new at agreenftp.no-ip.com Received: from agreenftp.no-ip.com ([127.0.0.1]) by localhost (zeus.agreenftp.no-ip.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id dLBIDuO9G+Aw; Fri, 17 Aug 2007 11:07:17 -0400 (EDT) Received: from [10.212.3.94] (216.215.144.201.nw.nuvox.net [216.215.144.201]) (Authenticated sender: andy) by agreenftp.no-ip.com (Postfix) with ESMTPA id 12BC03982A; Fri, 17 Aug 2007 11:07:16 -0400 (EDT) Message-ID: <46C5B9A2.3020305@gmail.com> Date: Fri, 17 Aug 2007 11:07:14 -0400 From: Andy Greenwood User-Agent: Thunderbird 2.0.0.6 (Windows/20070728) MIME-Version: 1.0 To: Jerry McAllister References: <098C8817-8D41-4D94-96E2-97D4310B0BAE@gmail.com> <20070817145551.GA27837@gizmo.acns.msu.edu> In-Reply-To: <20070817145551.GA27837@gizmo.acns.msu.edu> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Nicholas Wieland , freebsd-questions@freebsd.org Subject: Re: Swap size 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: Fri, 17 Aug 2007 15:07:21 -0000 Jerry McAllister wrote: > On Fri, Aug 17, 2007 at 02:05:57AM +0200, Nicholas Wieland wrote: > > >> I was reading tuning(7), and I found that I should size my swap >> double the size of my physical memory. >> AFAIK that was true some years ago, when memory was not as cheap as >> now, and following that guideline I should set my swap to 2GB, which >> seems far too much for swap (at least to me ...). I will never need >> this much memory as 1GB RAM and 2GB swap. >> Is it still correct ? How can I resize with bsdlabel if I already >> used all my disk space during install ? >> > > Remember, disk sizes have shot up too. > No, 2 GB is not excessive. You can get by with less, but you're > not likely to be using proportionately as much disk now as you used > to by going with 2X - I aim for a little over 2X. > > Remember that swap gets used for crash dumps and also for paging. > Now, you may think that you want to keep your machine from paging > and in one sense that is true. If you are so memory bound that > it has to page just to run, you're going to be so slow that it > seems to have froze (by today's standards). But, the system does > write stuff to page space and for processes that are often called > it can speed things up. > > So, it is not really a waste to assign that much to swap. > > ////jerry > > >> TIA, >> ngw >> >> -- >> Nicholas Wieland >> nicholas.wieland@gmail.com >> >> >> >> _______________________________________________ >> 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" >> > _______________________________________________ > 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" > My understanding was that you should estimate swap size based on the sizes of the programs which might be paged out. However, when I first set up my system, I didn't know this and created 1G swap slices (one on each disk) but I am not convinced that this was the best thing to do, since my system almost never uses a noticible percentage of the swap space. right now, I've got [andy@zeus fusefs-sshfs]$ swapinfo Device 1K-blocks Used Avail Capacity /dev/ad0s1b.eli 1048576 1148 1047428 0% /dev/ad1s1b.eli 1048576 1096 1047480 0% Total 2097152 2244 2094908 0% And the system is under normal load. This system has 1G of RAM. Is there any sense in having this much swap space when it's not being used?