From owner-freebsd-java Thu Nov 7 3:28:33 2002 Delivered-To: freebsd-java@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 6205637B401 for ; Thu, 7 Nov 2002 03:28:32 -0800 (PST) Received: from dire.bris.ac.uk (dire.bris.ac.uk [137.222.10.60]) by mx1.FreeBSD.org (Postfix) with ESMTP id 48BDE43E75 for ; Thu, 7 Nov 2002 03:28:31 -0800 (PST) (envelope-from Jan.Grant@bristol.ac.uk) Received: from mail.ilrt.bris.ac.uk by dire.bris.ac.uk with SMTP-PRIV with ESMTP; Thu, 7 Nov 2002 11:28:13 +0000 Received: from cmjg (helo=localhost) by mail.ilrt.bris.ac.uk with local-esmtp (Exim 3.16 #1) id 189kpM-0003Lu-00; Thu, 07 Nov 2002 11:28:00 +0000 Date: Thu, 7 Nov 2002 11:28:00 +0000 (GMT) From: Jan Grant X-X-Sender: cmjg@mail.ilrt.bris.ac.uk To: Erwan Arzur Cc: Aditya , freebsd-java Subject: Re: preventing the JVM from swapping to disk In-Reply-To: <3DCA3A2A.7030904@netvalue.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-java@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org On Thu, 7 Nov 2002, Erwan Arzur wrote: > Aditya wrote: > > On a server solely dedicated to running Tomcat with the linux-jdk1.3 and 1Gig > > of RAM I'd like to prevent the JVM from ever swapping to disk. The preferred > > behaviour when it runs out of memory is for the JVM to exit (it will be > > restarted by a script). I'm allocating the JVM 700M for the min and max heap; > > less than 100M is used by FreeBSD and the rest is occupied by the JVM. > > > > One piece of advice before blindly set -Xmx700m -Xms700m, make sure you > read this article : > http://www.javaworld.com/javaworld/jw-01-2002/jw-0111-hotspotgc_p.html > and all assorted references at the end of it. > > I really think FreeBSD VM subsystem requires you to allocate swap space. > I guess you'll get suboptimal performance results by simply disabling it. > > don't forget your dear google friend ;-) Or ask Matt Dillon; BSD copes perfectly well without swap. -- jan grant, ILRT, University of Bristol. http://www.ilrt.bris.ac.uk/ Tel +44(0)117 9287088 Fax +44 (0)117 9287112 http://ioctl.org/jan/ "...er, that's my _spare_ axe." - Gimli in the Council of Elrond, FotR. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-java" in the body of the message