Log file formats and the Btree, Recno and Hash Access Method database formats changed in the Berkeley DB 3.0 release. (The on-disk Btree/Recno format changed from version 6 to version 7. The on-disk Hash format changed from version 5 to version 6.) Until the underlying databases are upgraded, the DB->open() method will return a DB_OLD_VERSION error.

For further information on upgrading Berkeley DB installations, see Upgrading Berkeley DB installations.