From owner-freebsd-questions Tue Nov 27 1:53:57 2001 Delivered-To: freebsd-questions@freebsd.org Received: from freebie.atkielski.com (ASt-Lambert-101-2-1-14.abo.wanadoo.fr [193.251.59.14]) by hub.freebsd.org (Postfix) with ESMTP id D306B37C2C4 for ; Tue, 27 Nov 2001 01:52:45 -0800 (PST) Received: from contactdish (win.atkielski.com [10.0.0.10]) by freebie.atkielski.com (8.11.3/8.11.3) with SMTP id fAR9j2702670; Tue, 27 Nov 2001 10:45:02 +0100 (CET) (envelope-from anthony@freebie.atkielski.com) Message-ID: <006101c17728$2fdfae30$0a00000a@atkielski.com> From: "Anthony Atkielski" To: "Mike Meyer" Cc: References: <15363.11945.410356.244254@guru.mired.org><003701c17725$8abc5c20$0a00000a@atkielski.com> <15363.24098.8617.782371@guru.mired.org> Subject: Re: Calculating swap file size Date: Tue, 27 Nov 2001 10:45:01 +0100 Organization: Anthony's Home Page (development site) MIME-Version: 1.0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4522.1200 X-MIMEOLE: Produced By Microsoft MimeOLE V5.50.4522.1200 Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG The FAQ says: "Note that while FreeBSD is proactive in this regard [swapping pages out in anticipation of a need for memory], it does not arbitrarily decide to swap pages when the system is truly idle." As far as I can tell, my lightly loaded system never uses the swap file at all: freebie# swapinfo Device 1K-blocks Used Avail Capacity Type /dev/ad0s1b 819072 0 819072 0% Interleaved So it would appear that the swap file is not touched below some threshold of system activity. ----- Original Message ----- From: "Mike Meyer" To: "Anthony Atkielski" Cc: Sent: Tuesday, November 27, 2001 10:34 Subject: Re: Calculating swap file size > [Context recovered from top posting. > > Anthony Atkielski types: > > From: "Mike Meyer" > > > Anthony Atkielski types: > > > > Does FreeBSD resort to swap only when RAM is exhausted, or does it > > > > have to use the swap file all the time (as in a one-to-one VM > > > > mapping scheme)? > > > Neither. It doesn't do a ono-to-one VM scheme, but the system is > > > opportunistic about putting things on swap and tagging the page as > > > "free" if it can. > > If I understand you and others correctly, as long as all processes > > can be contained in RAM, swap space will never be used at all > > No, that's not the case, and I didn't say that was the case. Please > see the FAQ, section 13, question 1, for more information on that. > > -- > Mike Meyer http://www.mired.org/home/mwm/ > Q: How do you make the gods laugh? A: Tell them your plans. > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message