You can optionally assign a VSAM MASTERPW- or CONTROLPW-level password to protect all the VSAM data sets that make up the database. If you do, you must use it:
Table 14 shows how a CONTROLPW is to be coded. Coding for a MASTERPW is identical, except for the keyword.
Each time the application server is started, the DBPSWD=password initialization parameter must be supplied. The database manager uses the password when it opens the VSAM data sets. If the password supplied does not match the one defined for the data sets, the operator is prompted to supply the correct one. (See DBPSWD)