From owner-freebsd-security Wed Aug 11 11:52:16 1999 Delivered-To: freebsd-security@freebsd.org Received: from eagle.aitken.com (eagle.aitken.com [209.249.97.250]) by hub.freebsd.org (Postfix) with ESMTP id A7ADD155DE for ; Wed, 11 Aug 1999 11:52:12 -0700 (PDT) (envelope-from jaitken@aitken.com) Received: (from jaitken@localhost) by eagle.aitken.com (8.9.1a/8.9.1) id OAA21052; Wed, 11 Aug 1999 14:51:03 -0400 From: Jeff Aitken Message-Id: <199908111851.OAA21052@eagle.aitken.com> Subject: Re: 4 Swap partitions limit (was Re: RE: Little question (offtopic)) In-Reply-To: <14257.50009.162402.381699@trooper.velocet.ca> from David Gilbert at "Aug 11, 1999 02:39:21 pm" To: dgilbert@velocet.ca (David Gilbert) Date: Wed, 11 Aug 1999 14:51:03 -0400 (EDT) Cc: des@flood.ping.uio.no, jrs@enteract.com, fullermd@futuresouth.com, dillon@apollo.backplane.com, RCHILDER@hamquist.com, ripley@nostromo.in-berlin.de, freebsd-security@FreeBSD.ORG X-Mailer: ELM [version 2.4ME+ PL53 (25)] Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org David Gilbert writes: > One curious aspect of FreeBSD that I havn't explained to my own > satisfaction is why it appears to consume more swap than linux. From: http://www.freebsd.org/FAQ/FAQ235.html#238 12.1. FreeBSD uses far more swap space than Linux. Why? FreeBSD only appears to use more swap than Linux. In actual fact, it does not. The main difference between FreeBSD and Linux in this regard is that FreeBSD will proactively move entirely idle, unused pages of main memory into swap in order to make more main memory available for active use. Linux tends to only move pages to swap as a last resort. The perceived heavier use of swap is balanced by the more efficient use of main memory. Note that while FreeBSD is proactive in this regard, it does not arbitrarily decide to swap pages when the system is truely idle. Thus you will not find your system all paged out when you get up in the morning after leaving it idle overnight. --Jeff To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message