I have a Server with a Hyper-V Bare metal installed; and have six (6) virtual machines created on it. At first I used the Evaluation version of Windows Server 2016 on each VM, and now I want to improve to Windows Server 2016 Standard Version on each machine. The physical server have two CPU's with 10 cores each one, for a total of 20 cores. I have the following questions:
1. Should i buy a 20 cores license for each machine?
2. Once I have the licenses for each machine; how I can upgrade a these machines from the Windows Server 2016 Evaluation Version to the Standard Version?