For applications to connect using a server, the service must be started. If you stop a service, then it is temporarily unavailable, but is still subject to automatic restart and failover.
Enter the following SRVCTL syntax at the command line to start or stop a service:
$ srvctl start service -db db_unique_name [-service service_name_list] [-instance inst_name] [-startoption start_options]
$ srvctl stop service -db db_unique_name -service service_name_list [-instance inst_name] [-startoption start_options]