From owner-freebsd-questions Mon Mar 24 13:47:49 2003 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 83D0337B401 for ; Mon, 24 Mar 2003 13:47:44 -0800 (PST) Received: from mired.org (ip68-97-54-220.ok.ok.cox.net [68.97.54.220]) by mx1.FreeBSD.org (Postfix) with SMTP id 7470F43F75 for ; Mon, 24 Mar 2003 13:47:43 -0800 (PST) (envelope-from mwm-dated-1048974462.42fa56@mired.org) Received: (qmail 95299 invoked from network); 24 Mar 2003 21:47:43 -0000 Received: from localhost.mired.org (HELO guru.mired.org) (127.0.0.1) by localhost.mired.org with SMTP; 24 Mar 2003 21:47:43 -0000 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <15999.31998.368285.164467@guru.mired.org> Date: Mon, 24 Mar 2003 15:47:42 -0600 To: The Anarcat Cc: freebsd-questions@freebsd.org Subject: Re: crashdumping on massive amounts of RAM In-Reply-To: <20030324184555.GD831@lenny.anarcat.ath.cx> References: <20030324174332.GB831@lenny.anarcat.ath.cx> <15999.18326.297880.599596@guru.mired.org> <20030324184555.GD831@lenny.anarcat.ath.cx> X-Mailer: VM 7.07 under 21.1 (patch 14) "Cuyahoga Valley" XEmacs Lucid X-face: "5Mnwy%?j>IIV\)A=):rjWL~NB2aH[}Yq8Z=u~vJ`"(,&SiLvbbz2W`; h9L,Yg`+vb1>RG% *h+%X^n0EZd>TM8_IB;a8F?(Fb"lw'IgCoyM.[Lg#r\ From: Mike Meyer X-Delivery-Agent: TMDA/0.71 (Hoop, Jr.) X-Spam-Status: No, hits=-19.5 required=5.0 tests=FROM_ENDS_IN_NUMS,IN_REP_TO,QUOTED_EMAIL_TEXT, QUOTE_TWICE_1,REFERENCES,REPLY_WITH_QUOTES autolearn=ham version=2.50 X-Spam-Level: X-Spam-Checker-Version: SpamAssassin 2.50 (1.173-2003-02-20-exp) 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 In <20030324184555.GD831@lenny.anarcat.ath.cx>, The Anarcat typed: > On Mon Mar 24, 2003 at 11:59:50AM -0600, Mike Meyer wrote: > > In <20030324174332.GB831@lenny.anarcat.ath.cx>, The Anarcat typed: > > > I am fortunate enough to have a box with a lot (by my standards) of > > > RAM: > > > Any brilliant ideas to work around this? > > Yes - enable the kernel debugging option (DDB) on the kernel, and > > debug the running system when it panics. > The only problem I see with that is with non-reproducable panics, if I > don't debug *everything* properly the first time, I might not be able > to get back all the data I need. Yup, it's not as handy as having a dump. But dumps happen to swap, so you have to have a first swap partition that's at least 64K bigger than main memory. > > As for your swap partition - the same thing happens when you run out > > of virtual memory either way: processes start dieing. Having a little > > swap lets you get a warning of that because you'll start paging things > > out which would otherwise live in memory. Unless you're planning on > > setting up a warning system that watches for paging activity and > > notifies you so you can do something about it, there's probably not > > much point in having 250MB of swap on a system with a gigabyte of > > ram. In your shoes, I'd seriously consider running without swap. > I've considered it, but I found that I've been able to run over 1GB of > mem, so the 250MB is handy to handle exceptional situations as the > disk slows down allocation. If you've just run through a gigabyte of real ram, how long does an extra 250mb last you? > > On the other hand, disk space is so cheap that I always have lots of > > swap. Something about the days when I used to recompile LISP systems > > on memory-starved machines.... > Eh. It's a 40GB disk and I really considered putting 1GB of it for > swap. I've got a gigabyte of swap with only 20GB of real space. Of course, I use swap for /tmp with an mfs-backed file system. http://www.mired.org/consulting.html Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message