When a system becomes unresponsive, without any messages provided for diagnosis of the problem, the deadman kernel code can be enabled to force a core dump during the systems unresponsive period. However if the system is equipt with an ALOM, there is a function known as the ALOM watchdog which will reset them system according to set perameters when the system goes unresponsive. By default the watchdog will just power cycle the system, however this gathers no addition as to the cause of the unresponsive period for the system.
You can set the watchdog to dump a corefile however with the following command:
This effectively will turn the LOM watchdog into the deadman timer.