Date: Wed, 05 Dec 2007 06:16:54 -0600 From: Derek Ragona <derek@computinginnovations.com> To: yar <owensr57@gmail.com>, freebsd-questions@freebsd.org Subject: Re: What is best method to debug freezes/hangs? Message-ID: <6.0.0.22.2.20071205060729.024bd7a0@mail.computinginnovations.com> In-Reply-To: <14164268.post@talk.nabble.com> References: <14164268.post@talk.nabble.com>
next in thread | previous in thread | raw e-mail | index | archive | help
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.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?6.0.0.22.2.20071205060729.024bd7a0>