In an unmanaged z/OS server, stateful session bean failover among servants can be enabled.
Failover only occurs between the servants of a given unmanaged server. If an unmanaged z/OS server has only one servant, then enabling failover has no effect. An unmanaged z/OS server that has failover enabled does not fail over to another unmanaged z/OS server.
Failover in an unmanaged server is enabled by setting a JVM property.