If you run the Set CPU Resources action with an unsupported value on a virtual machine, the task fails and an error appears in the Recent Task messages.
The Recent Tasks list indicates that a Set CPU Resource or Set Memory Resource action has a state of Failed. When you evaluate the Messages list for the selected task, you see a message similar to the following examples.
RuntimeFault exception, message:[A specified parameter was not correct. spec.cpuAllocation.reservation]
RuntimeFault exception, message:[A specified parameter was not correct. spec.cpuAllocation.limits]
You submitted the action to increase or decrease the CPU or memory reservation or limit value with an unsupported value. For example, if you supplied a negative integer other than -1, which sets the value to unlimited, vCenter Server could not make the change and the action failed.
The supported values for reservation include 0 or a value greater than 0. The supported values for limit include -1, 0, or a value greater than 0.