Veritas Cluster Server (VCS) from Symantec connects multiple, independent systems into a management framework for increased availability. VCS links commodity hardware with intelligent software to provide application failover and control. VCS detects failure of an application by issuing specific commands, tests, or scripts to monitor the overall health of an application. VCS also determines the health of underlying resources supporting the application, such as file systems and network interfaces. VCS uses a redundant network heartbeat to discriminate between the loss of a system and the loss of communication between systems.