Start using datapump export

Execute the following commands to create a database directory. This directory must point to a valid directory on the same server as the database:
SQL> CREATE DIRECTORY dmpdir AS '/opt/oracle';
Directory created.

SQL> GRANT read, write ON DIRECTORY dmpdir TO scott;
Grant succeeded.


PS: Oracle introduced a default directory from 10g R2, called DATA_PUMP_DIR, that can be used:
SQL> SELECT directory_path FROM dba_directories WHERE directory_name = 'DATA_PUMP_DIR';

DIRECTORY_PATH
--------------------------------------------------------------------------------
/app/oracle/product/10.2.0/rdbms/log/