There are situations when you need to check cluster reactions after a ESX host crash. For example to see if HA will start VM on other hosts.
The easiest method is to pull a hosts powercord. But there ar more elegant ways to let a host crash.
Warning! Do not use on productive systems! This is for testing purposes under controlled conditions only. Use at your own risk.
PSOD
You can trigger a Purple-Screen-of-Death (PSOD) by issuing a special command that causes a kernel panic. Use the VMkernel Sys Info Shell (vsish).
First you need a SSH connection to your host. Change to vsish
vsish set /reliability/crashMe/Panic
Alternatively you can issue the command together with parameters.
vsish -e set /reliability/crashMe/Panic 1
Your host will end up in a PSOD and can be restarted afterwards.