On Windows operating systems, the database instance that is created during install is set as auto-started by default. An instance created using db2icrt is set as a manual start. To change the start type, you must go to the Services panel and change the property of the DB2® service there.
db2iauto -on <instance name>
where <instance
name> is the login name of the instance.On UNIX operating
systems, to prevent an instance from auto-starting after each system
restart, enter the following command: db2iauto -off <instance name>
where <instance
name> is the login name of the instance.