Check manual page of esx_vsphere_hostsystem_state
|VMware ESX Host System: Overall State and Power State|
|Distribution||Official part of Checkmk|
OK if the ESX host is running normally (powered on)
WARN if vsphere reports overall state of yellow or if the ESX host is in power state standBy
CRIT if vsphere reports overall state of red or grey or if the ESX host is in power state poweredOff
See "Monitoring VMware ESX with Checkmk" in the online documentation as well.
One service is created for each ESX Host System.