You must register Oracle Database Vault with Oracle RAC database and create database user accounts before you can use Oracle Database Vault feature.

Oracle Universal Installer (OUI) installs Oracle Database Vault by default when you install the Oracle Real Application Clusters (Oracle RAC) software, but you must register Oracle Database Vault with the Oracle RAC database and create database user accounts before you can use it. You must create the Database Vault Owner user and, optionally, the Database Vault Account Manager administrative user accounts.