> Any idea how to diagnose the problem? Turn on as much verbose logging as you can and see what you get. Do you get any kernel crash messages on the console when the machine hangs or does it just hang up and die?
Your first port of call is to get the system logs out of the machine. Sending them to the console is a start. Sending them to another machine via serial will let you go back through them after it's crashed and look for symptoms. I don't know enough about the guts of OpenBSD to help diagnose the crash, but is there a way to turn on verbose kernel logging? If there is that would help narrow things down a little. It's difficult to diagnose a problem like this, but clear your mind of assumptions. It could be anything - bad memory, bad CPU, bad network card, bad software, bad disks, etc. You need to start ruling out all of those things. In my experience hard lockup are almost always due to failing hardware rather than the OS (unless you're running unstable development drivers for bleeding edge hardware). Memory can be stressed by hefty compiles. Building the kernel is a good test. Does a kernel compile succeed? How about if you use make -j 4 to run 4 tasks in parallel and use up more RAM? That also stresses the CPU. You could boot one of those *cough* Linux live CDs with a memory tester on it and run a memory test overnight to look for failures but that's not reliable in many border cases. Are the disks OK? Smart can be used to check for some kinds of errors. Look in the logs for disk access failures. Finally, if you think it's network related unplug the network and stress test the machine. Try a different NIC if you have one lying about. Regards, A
