It should be possible to install the Diagnostic Server on a VMware if the machine’s MAC address is static.
Diagnostics server’s license depends on the MAC address which by default is dynamic on a VMware. Please contact your system administrator to perform the necessary adjustments to make the VMware MAC address static. The following VMware knowledge base article describes how to do so:
The installation of the Mediator component should not be a problem from a licensing point of view as Diagnostic license uses the Diagnostic Server’s MAC address and not the Mediator’s MAC address.