Editing a VM while it is online

Hi,

i want to edit my VM while it is running.

So I want to change the RAM Size of my virtual Machine. My first taught was to it with a ConfigSpec, but I got an expection, that it is not possible in this state.

It will generate my next try, but how can i manipulate the config over the API? Like vm.summary.config.memorySizeMB = 2048 ?

vRA and PowerCLI do not make any other way, they editing the vmx file over the API. How could the way be for the orchestrator.