From owner-freebsd-questions@FreeBSD.ORG Fri Sep 29 15:58:40 2006 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 80F4116A40F for ; Fri, 29 Sep 2006 15:58:40 +0000 (UTC) (envelope-from lists@jnielsen.net) Received: from ns1.jnielsen.net (ns1.jnielsen.net [69.55.238.237]) by mx1.FreeBSD.org (Postfix) with ESMTP id ACAAD43D55 for ; Fri, 29 Sep 2006 15:58:39 +0000 (GMT) (envelope-from lists@jnielsen.net) Received: from localhost (jn@ns1 [69.55.238.237]) (authenticated bits=0) by ns1.jnielsen.net (8.12.9p2/8.12.9) with ESMTP id k8TFwcCJ022290; Fri, 29 Sep 2006 08:58:38 -0700 (PDT) (envelope-from lists@jnielsen.net) From: John Nielsen To: freebsd-questions@freebsd.org Date: Fri, 29 Sep 2006 11:58:25 -0400 User-Agent: KMail/1.9.4 References: In-Reply-To: X-Face: #X5#Y*q>F:]zT!DegL3z5Xo'^MN[$8k\[4^3rN~wm=s=Uw(sW}R?3b^*f1Wu*.<=?utf-8?q?of=5F4NrS=0A=09P*M/9CpxDo!D6?=)IY1w<9B1jB; tBQf[RU-R<,I)e"$q7N7 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200609291158.25518.lists@jnielsen.net> X-Virus-Scanned: ClamAV version 0.88.4, clamav-milter version 0.88.4 on ns1.jnielsen.net X-Virus-Status: Clean Cc: Chris Subject: Re: Swap Size Importance? 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, 29 Sep 2006 15:58:40 -0000 On Friday 29 September 2006 11:52, Chris wrote: > As a standard practice, I've always configured swap file to be double > the size of real ram split across system and data disk. For example, > 8gb on da0 and 8gb on da1 if the system has 8g real ram. In practice, > In 7 or 8 years, I've never seen swap used for anything but a few k > of inactive processes and I would imagine if real active process > swapping occurred, it would be an immediate indicator that the system > that isn't responsive enough for use anymore and requires upgrade or > tuning. Can't run a website process off disk and keep anyone coming > to the site ;-). (BTW, I'm talking only about high end servers, not > test boxes where I've seen lots of swapping). > > I'm at the point of attempting my first gvinum software raid-5 and > realized, I need the entire disk storage of all three non-system > drives to avoid pulling an 8gb chunk out of the drive sizes. The > configuration is one scsi 72g system disk and 3 that will be used for > the raid volume. I should mention I turn off dumps, haven't found the > use for that in a production server since it should not be rebooting > or it's back in the shop and another box is taking it's place. > > Is there any shortfall in performance or reliability to running > production with swap equal in size to the 8gb of system memory? I > can't think of any but don't want to make a hard to correct mistake > once this thing goes in. Nope. I routinely run boxes with 512MB or 1GB of swap, even if the RAM size is much higher than that. You won't have anywhere to save a crashdump in that case, but you seem to already be aware of that. JN