In a server cluster, Backup Exec can protect data on local disks and shared disks, as well as protect Microsoft SQL and Exchange databases that are configured as virtual server applications; that is, they contain an IP address resource, a Network Name resource, and are displayed on the network with a unique server name (the virtual server name). Clustered servers provide high availability of applications and data to users. In a clustered server, several servers (called nodes) are linked in a network, and run cluster software that allows each node access to the shared disks. If a node becomes unavailable, cluster resources migrate to an available node (called failover). The shared disks and the virtual server are kept available. During failover, users experience only a short interruption in service.