How do I know which Windows Server 2008 features or services I am allowed to run on the host without requiring CALs?
A. When using Windows Server 2008 and Hyper-V to run virtual machines with older versions of Windows Server, Windows Server 2008 CALs will not be required in certain scenarios. When the Host OS is only running services related to virtualization, such as Hyper-V and Failover Clustering, then Windows Server 2008 CALs are not required.If the Guest OS is Windows Server 2008, or if the Windows Server 2008 host, installs other services, then WS08 CALs would still be required.