Each virtual machine you power on requires a certain amount of memory for its use. In addition, the host must have some memory overhead available for each virtual machine. To find out about memory overheat, call the HostSystem.QueryMemoryOverheadEx method. The method takes a virtualMachineConfigInfo data object as an argument, and determines the amount of overhead necessary to power on a virtual machine with those characteristics.

The methods returns the amount of memory required, in bytes.