To enable Oracle file mapping with the Veritas Storage Mapping option
# cd $ORACLE_HOME/rdbms/filemap/etc
For 64-bit Oracle, the filemap.ora file should contain the following setting:
SQL> alter system set file_mapping=true;
The file_mapping initialization parameter is set to false by default. You do not need to shut down the instance to set this parameter. Setting file_mapping=true starts the FMON background process.
If you want storage mapping to be enabled whenever you start up an instance, set the file_mapping initialization parameter to true in the init.ora file.