A systems administrator must license a new network-monitoring application that is sold under a per-server model. The planned production environment consists of two physical hypervisor hosts. Each host will run four Linux virtual machines (VMs), and every VM will execute its own copy of the monitoring server software. No other instances of the product will be installed. Ignoring any client access licenses, what is the minimum number of server licenses the organization must purchase to stay compliant with the vendor's per-server licensing terms?
Under a per-server model, you need one license for every running instance of the server software, whether that instance is on bare metal or inside a VM. Because each of the two hosts will run four VMs and each VM runs its own copy of the application, there will be 2 hosts × 4 VMs = 8 separate server instances. Therefore, eight server licenses are required. Purchasing only two or four licenses would cover the physical hosts or half of the VMs but would leave some running instances unlicensed, and buying sixteen licenses would exceed what is necessary.