Example: An Organization Designs a Clustered File Server

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

A large organization uses centralized file servers to store home directories for 3,000 users. The organization has an existing SLA that specifies its file servers must be 99.99 percent available, which means that the file servers can be offline no more than 53 minutes a year. To meet this level of availability, the organization implements clustered file servers in its data center, using a storage area network (SAN) for storage.

After evaluating storage and performance requirements, the organization determines that it needs one file server per 1,000 users, for a total of three file servers. The organization could implement a three-node cluster, but it decides to implement a four-node cluster instead. It will use three nodes to provide access to user directories and the fourth node to perform the following functions:

• Host a stand-alone DFS namespace to provide a unified view of the user directories on the remaining three nodes.

• Perform backups of the other three nodes in the evenings.

• Take over the resources of another node if the node fails or is taken offline for maintenance.

Figure 2.16 illustrates how the organization designs its four-node cluster.

Figure 2.16   Four-Node Cluster

To create the user directories, the administrator creates a File Share resource on three nodes and specifies the Share Subdirectories option. The administrator places each File Share resource in a virtual server (a resource group containing IP address and Network Name resources) and sets up dependencies between the File Share resource and the Network Name resource. The administrator then uses a script to quickly create the user directories, which are automatically shared after creation, and to set appropriate permissions for each user directory. The administrator creates another File Share resource on the fourth node and specifies the DFS root option and then uses the Distributed File System snap-in to create a link to each user directory. Users can access their shares by using the DFS path \\Home\Folders\Username. Logon scripts also map user shares to each user’s U: drive.

Note

• If the organization needs to provide access to user data when the complete site fails, due either to a total loss of power as a result of a natural disaster or another event, the organization can implement a geographically dispersed cluster.

For more information about designing server clusters, including capacity planning, failover policies, and geographically dispersed clusters, see "Designing and Deploying Server Clusters" in this book.