The agent enables VCS to determine the status of parallel service groups that do not include OnOff resources, which are resources that VCS can start and stop. Without the "dummy" resource provided by this agent, VCS cannot assess the status of groups that only contain None (Persistent) and OnOnly resources because the state of these resources is not considered in the process of determining whether a group is online. Refer to the VCS Administrator's Guide for information on categories of service groups and resources.

Do not use the Phantom resource in failover service groups.

Also, the Phantom resource should not be used in service groups that don't contain any resources.