Agents are VCS processes that manage predefined resource types. SFCFSHA and CVM require agents to interact with VCS. Agents bring resources online, take resources offline, monitor resources, and report any state changes to VCS. VCS bundled agents are part of VCS and are installed when VCS is installed. The SFCFSHA and CVM agents are add-on resources to VCS specifically for the Veritas File System and Veritas Volume Manager.
See the Storage Foundation Cluster File System High Availability Installation Guide.