What is best method to debug freezes/hangs?

[yar]

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
-- 
View this message in context: http://www.nabble.com/What-is-best-method-to-debug-freezes-hangs--tf4947151.html#a14164268
Sent from the freebsd-questions mailing list archive at Nabble.com.