From owner-freebsd-questions Wed Mar 25 20:30:21 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id UAA09940 for freebsd-questions-outgoing; Wed, 25 Mar 1998 20:30:21 -0800 (PST) (envelope-from owner-freebsd-questions@FreeBSD.ORG) Received: from allegro.lemis.com (allegro.lemis.com [192.109.197.134]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id UAA09916 for ; Wed, 25 Mar 1998 20:30:01 -0800 (PST) (envelope-from grog@lemis.com) Received: from freebie.lemis.com (freebie.lemis.com [192.109.197.137]) by allegro.lemis.com (8.8.7/8.8.5) with ESMTP id OAA22719; Thu, 26 Mar 1998 14:59:57 +1030 (CST) Received: (from grog@localhost) by freebie.lemis.com (8.8.8/8.8.7) id OAA00664; Thu, 26 Mar 1998 14:59:56 +1030 (CST) (envelope-from grog) Message-ID: <19980326145956.12247@freebie.lemis.com> Date: Thu, 26 Mar 1998 14:59:56 +1030 From: Greg Lehey To: "Daniel R. Brownstone" Cc: questions@FreeBSD.ORG Subject: Re: Optimizing FreeBSD References: <19980326122209.64374@freebie.lemis.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.89i In-Reply-To: ; from Daniel R. Brownstone on Wed, Mar 25, 1998 at 08:09:27PM -0600 WWW-Home-Page: http://www.lemis.com/~grog Organization: LEMIS, PO Box 460, Echunga SA 5153, Australia Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-41-739-7062 Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Wed, 25 March 1998 at 20:09:27 -0600, Daniel R. Brownstone wrote: > On Thu, 26 Mar 1998, Greg Lehey wrote: > >> FreeBSD adapts to the user load much better than earlier versions of >> UNIX did, so there's not much call for the kind of optimization that I >> suspect you're talking about. In general, unless you have performance >> problems, you don't need to do much. If you do have problems, you >> need to address them individually. On this list, this means you need >> to tell us what the problems are. > > Funny you should mention that. > > We have up to about 30 users logged on simulatenously, some via modem (up > to 56k), and the rest via 100 Base T. Recently (the last couple of > months) at various times -- usually during heavy usage -- the system will > slow down very quickly, and finally just freeze up, with the only solution > being to do a hard reboot. Very annoying. I can't find any processes > that are always running at the time, and with my lack of sophistication, I > can't otherwise diagnose the error. When this all started, we were > running 2.2-SNAP from like October 96, and so I upgraded to 2.2.5-STABLE. > However, the problem has not corrected itself. Hmmm. I wouldn't consider this a matter for tuning. I'd call it a bug. > One thing of interest is that when the system does lock up, the "IN USE" > light on one of the hard drives is always on solid. Near as I can tell, > however, it's not always the same drive. > > The system is a Proliant 5000 with 256 MB of RAM and a few GB of storage. > > Does that help? It brings us a lot closer. Let's consider what it could be: 1. You mention a disk light being on. This could be a clue, but I've noticed that happening a number of times when disk access wasn't the problem, so we should defer that until we have to look at it. 2. You have a 100 BaseT network. What kind of board? Could be that there are problems with the driver. Could be that they're coupled with problems with the net (bad cable, for example). 3. You say the system slows down over a period of time. Is this the case from the console as well? Maybe you can recognize some kind of unusual circumstance, like excessive retransmits or such. I can't tell you where to look here, just how to go about looking for it. 4. You should consider building a debug kernel with the kernel debugger. You can strip the kernel before booting, but you need the debug version (about 10 MB) for dump analysis. Take a look at the online handbook for more details. That way we at least have an idea of what has gone wrong. Greg To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message