Roles, Role Services, and Features
Applies To: Windows Server 2008
Server Manager in Windows Server® 2008 replaces older management consoles such as Configure Your Server and Manage Your Server. With Server Manager, you prepare your server for deployment by installing logical software packages known as roles, role services, and features.
This topic defines what roles, role services, and features are, and how they are integrated in your enterprise.
What are server roles, role services, and features?
This section defines the terms role, role service, and feature as they apply to Windows Server 2008.
Roles
A server role is a set of software programs that, when installed and properly configured, allows a computer to perform a specific function for multiple users or other computers within a network. Generally speaking, roles share the following characteristics:
They describe the primary function, purpose, or use of a computer. A specific computer can be dedicated to perform a single role that is heavily used in the enterprise, or may perform multiple roles if each role is only lightly used in the enterprise.
They provide users throughout an organization access to resources managed by other computers, such as Web sites, printers, or files stored on different computers.
They typically include their own databases, which can queue user or computer requests, or record information about network users and computers that relates to the role. For example, Active Directory Domain Services includes a database for storing the names and hierarchical relationships of all computers in a network.
Once properly installed and configured, roles are designed to function automatically, allowing the computers on which they are installed to perform prescribed tasks with limited user commands or supervision.
Role services
Role services are software programs that provide the functionality of a role. When you install a role, you can choose which role services the role will provide for other users and computers in your enterprise. Some roles, such as DNS Server, have only a single function, and therefore do not have available role services. Other roles, such as Terminal Services, have several role services that can be installed, depending on the remote computing needs of your enterprise.
You can consider a role as a grouping of closely related, complementary role services, for which, in the majority of cases, installing the role means installing one or more of its role services.
Features
Features are software programs that, though they are not directly parts of roles, can support or augment the functionality of one or more roles, or enhance the functionality of the entire server, regardless of which roles are installed. For example, the Failover Clustering feature augments the functionality of other roles, such as File Services and DHCP Server, by enabling them to join server clusters for increased redundancy and improved performance. Another feature, Telnet Client, allows you to communicate remotely with a telnet server over a network connection, functionality which enhances the communication options of the server as a whole.
Dependencies in Server Manager
As you install roles and prepare to deploy your server, Server Manager prompts you to install any other roles, role services, or features that are required by a role you want to install. For example, many roles, such as UDDI Services, require Web Server (IIS) to run.
Similarly, if you want to remove roles, role services, or features from your computer, messages from Server Manager show you if other programs require the software you are removing. For example, if you want to remove Web Server (IIS), Server Manager alerts you if other roles that depend on Web Server (IIS) remain on the computer. This complex arrangement of software dependencies is managed by Server Manager and prevents the accidental removal of software that the server requires to perform its assigned tasks. Users are not required to know on what software the roles they want to install depend.
For more information about dependencies, see Role, Role Service, and Feature Dependencies in Server Manager.