From owner-freebsd-questions@FreeBSD.ORG Wed Dec 5 12:17:18 2007 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id EF1A716A469 for ; Wed, 5 Dec 2007 12:17:18 +0000 (UTC) (envelope-from derek@computinginnovations.com) Received: from betty.computinginnovations.com (mail.computinginnovations.com [64.81.227.250]) by mx1.freebsd.org (Postfix) with ESMTP id 95FB013C46B for ; Wed, 5 Dec 2007 12:17:18 +0000 (UTC) (envelope-from derek@computinginnovations.com) Received: from p28.computinginnovations.com (dhcp-10-20-30-100.computinginnovations.com [10.20.30.100]) (authenticated bits=0) by betty.computinginnovations.com (8.13.8/8.13.8) with ESMTP id lB5CHATY042242; Wed, 5 Dec 2007 06:17:11 -0600 (CST) (envelope-from derek@computinginnovations.com) Message-Id: <6.0.0.22.2.20071205060729.024bd7a0@mail.computinginnovations.com> X-Sender: derek@mail.computinginnovations.com X-Mailer: QUALCOMM Windows Eudora Version 6.0.0.22 Date: Wed, 05 Dec 2007 06:16:54 -0600 To: yar , freebsd-questions@freebsd.org From: Derek Ragona In-Reply-To: <14164268.post@talk.nabble.com> References: <14164268.post@talk.nabble.com> Mime-Version: 1.0 X-ComputingInnovations-MailScanner-Information: Please contact the ISP for more information X-ComputingInnovations-MailScanner: Found to be clean X-ComputingInnovations-MailScanner-From: derek@computinginnovations.com X-Spam-Status: No Content-Type: text/plain; charset="us-ascii"; format=flowed X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: Subject: Re: What is best method to debug freezes/hangs? 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: Wed, 05 Dec 2007 12:17:19 -0000 At 08:49 PM 12/4/2007, yar wrote: >My question is how best to go about debugging sporadic freezes and hangs. >Just looking for general methods. On a couple of our IDS systems there >are sporadic hangs or freezes that occur every couple weeks or so, that are >recoverable by either system reboots or taking out and reinserting the Gig >fiber ethernet sniffing cables, but I never can find anything in >/var/logs/messages to tell what is going on. I'm assuming that may have to >compile in kernel debugger support, but from what I read briefly, doesn't >that require an actual crash with the resultant reboot and a debugger >readable file left in /var/crash? That doesn't happen, there is no >automatic reboot just a freeze/hang (box falls off network and at the >console unable to type until one of the two above mentioned measures are >take. The systems are: > >Dell 1850's >Free BSD 6.2 >2 Gb ram >running various open source IDS software BRO > >Thanks I would be sure your systems are running the generic kernel, or as close to generic that is possible to rule out anything you could have introduced by running a custom kernel. I would also run complete diagnostics on the hardware to rule out any hardware issues. You can also gather some information by having a script run top periodically and logging this to a file to see what the system is doing. You can check the last log entry of this file after a freeze/hang to see what was going on. -Derek -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. MailScanner thanks transtec Computers for their support.