Application Server The Application Server role of Windows Server provides an integrated environment for deploying and running server-based business applications, whether they are Microsoft or third-party applications. An Application Server using Windows Server 2008 requires server or processor licenses depending on the edition. Additionally, users or devices accessing an application server require CALs. When a server is not enabled with the Application Server role but is running Windows Server and Microsoft® Exchange Server, SQL Server software, or another Microsoft or third-party application, Windows Server license and CAL requirements still apply. One additional point of guidance: If you have more server or CAL licenses of a specific application than Windows Server licenses, then you are probably under-licensed for Windows Server. Consolidation server roles One way you can greatly simplify your licensing requirements is by using virtualization technology to consolidate multiple server functions or roles onto fewer servers. You can use Microsoft Hyper-V™ technology or third-party hypervisor products to create and manage virtual machines and their resources. Each virtual machine is a virtualized computer system that operates in an isolated execution environment. This means you can simultaneously run multiple instances of an operating system on a single physical server. For example, both Windows Server 2008 Enterprise and Windows Server 2008 Datacenter can run any number of virtual instances of the software for various server functions on each licensed physical server. As a result, you can accomplish the same goals with fewer servers, thus eliminating the need to license each separate server for a particular role. (You can virtualize with Windows Server 2008 Standard as well, but because you need to separately license each server instance, you’re only saving on hardware costs.) Virtualization does not reduce the number of CALs required—the users and devices accessing the Windows Server software must still be properly licensed. However, if you are using a server only as a hypervisor for a version of Windows Server earlier than 2008, you need a CAL just for the version of Windows being hosted. For example, if you are using Windows Server 2008 solely as a hypervisor for Windows Server 2003, then you only need Windows Server 2003 CALs, even though you are indirectly accessing Windows Server 2008. For more detailed Windows Server licensing information, please refer to the and the .
Application Server The Application Server role of Windows Server provides an integrated environment for deploying and running server-based business applications, whether they are Microsoft or third-party applications. An Application Server using Windows Server 2008 requires server or processor licenses depending on the edition. Additionally, users or devices accessing an application server require CALs. When a server is not enabled with the Application Server role but is running Windows Server and Microsoft® Exchange Server, SQL Server software, or another Microsoft or third-party application, Windows Server license and CAL requirements still apply. One additional point of guidance: If you have more server or CAL licenses of a specific application than Windows Server licenses, then you are probably under-licensed for Windows Server. Consolidation server roles One way you can greatly simplify your licensing requirements is by using virtualization technology to consolidate multiple server functions or roles onto fewer servers. You can use Microsoft Hyper-V™ technology or third-party hypervisor products to create and manage virtual machines and their resources. Each virtual machine is a virtualized computer system that operates in an isolated execution environment. This means you can simultaneously run multiple instances of an operating system on a single physical server. For example, both Windows Server 2008 Enterprise and Windows Server 2008 Datacenter can run any number of virtual instances of the software for various server functions on each licensed physical server. As a result, you can accomplish the same goals with fewer servers, thus eliminating the need to license each separate server for a particular role. (You can virtualize with Windows Server 2008 Standard as well, but because you need to separately license each server instance, you’re only saving on hardware costs.) Virtualization does not reduce the number of CALs required—the users and devices accessing the Windows Server software must still be properly licensed. However, if you are using a server only as a hypervisor for a version of Windows Server earlier than 2008, you need a CAL just for the version of Windows being hosted. For example, if you are using Windows Server 2008 solely as a hypervisor for Windows Server 2003, then you only need Windows Server 2003 CALs, even though you are indirectly accessing Windows Server 2008. For more detailed Windows Server licensing information, please refer to the and the .
Assessing_Windows_Server_Licensing.docx