I've to solve a nasty problem on a ten machine "cluster": randomly one of these machine hang during an hard computation, sometime still ping sometime not.

The problem was described me at the phone, I've still no touch/see these machine, so I can't be more precise. It seem there's no (real) keyboard or monitor linked to them, so I haven't nothing about keyboard led or messages on monitor.

Don't worry, what I really need is some suggestion where to search the problem, some suggestions on what can cause a kernel hang on a working machine.

I also see this post, but seem same need on a different situation.

My ideas since now:
- HW problem (ram, cpu, fan etc.)
- bad autofs configuration
- bad nfs(?) configuration
- presence of a trojan/hacker/etc
- /dev/"swap" linked to /dev/zero
- kernel out of memory(??)
- kernel bugged

In other words I try to imagine what kind of envent can occour that can crash the kernel insted of the application that generate the event.

What hang have YOU experienced before? Write it to me!

TIA