From owner-freebsd-questions Tue Jul 9 13:49:45 1996 Return-Path: owner-questions Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id NAA06114 for questions-outgoing; Tue, 9 Jul 1996 13:49:45 -0700 (PDT) Received: from relay-4.mail.demon.net (relay-4.mail.demon.net [158.152.1.108]) by freefall.freebsd.org (8.7.5/8.7.3) with SMTP id NAA06083 for ; Tue, 9 Jul 1996 13:49:35 -0700 (PDT) Received: from post.demon.co.uk ([158.152.1.72]) by relay-4.mail.demon.net id aa16295; 9 Jul 96 20:45 GMT Received: from jraynard.demon.co.uk ([158.152.42.77]) by relay-3.mail.demon.net id aa01532; 9 Jul 96 20:50 +0100 Received: (from fqueries@localhost) by jraynard.demon.co.uk (8.6.12/8.6.12) id OAA01235; Tue, 9 Jul 1996 14:52:41 GMT Date: Tue, 9 Jul 1996 14:52:41 GMT Message-Id: <199607091452.OAA01235@jraynard.demon.co.uk> From: James Raynard To: metcalf@imagine.com CC: questions@freebsd.org In-reply-to: <31E19354.4097@imagine.com> (metcalf@imagine.com) Subject: Re: Increase swap space? Sender: owner-questions@freebsd.org X-Loop: FreeBSD.org Precedence: bulk > I recently upgraded my RAM from 16MB to 32MB. I typically run > the following applications on FreeBSD: > > Netscape, TeX, emacs, and gcc I can see why you wanted more RAM :-) > There will probably never be any more than two users on my system > at any given time. When I installed FreeBSD, I only dedicated > 32MB to swap space. I have read some discussion that swap space > for FreeBSD should be 32MB or 2.5 times physical memory, whichever > is larger. It depends on your usage patterns. Twice physical memory is probably the minimum; if you're into heavy usage, (such as having at least one copy of all the above programs running under X), you may find you need 3 or 4 times physical RAM. As someone else has suggested, the best idea is to measure your usage and see if you're regularly running short of swap. (You'll probably notice if you run out completely, as the system will start killing things to try and free up some space). > Do you feel that I should increase swap space to get the optimal > benefit from my new RAM upgrade? If so, is there a way to do this > without reinstalling FreeBSD? I noticed some discussion in the > FreeBSD FAQ concerning adding swap space. Should I just follow > the procedure, or are there other concerns here? The FAQ describes a method of swapping onto a regular file. As far as I know, this works, but the performance isn't as good as with a "real" swap partition, as any accesses have to go through the filesystem. The optimal solution is probably to add another disk and put a swap partition on it. A SCSI bus can access multiple swap partitions in parallel, giving a performance boost, although you probably won't see one under IDE. (And of course you also get lots more disk space to play with!) -- James Raynard, Edinburgh, Scotland james@jraynard.demon.co.uk http://www.freebsd.org/~jraynard/