This forum is for Oracle Forms only. You have a better chance of getting your question answered if you post it in the correct forum. I would recommend Oracle Database at a minimum. A better forum might be the Recovery Manager (RMAN) forum.
I'll back up what craig said, i.e. this forum is for forms only, you should be looking in the dba forum for this sort of question.
I couldn't let the other response pass without comment however. Imp and exp is probably the worst way of backing up your database, you should be using the rman tool to backup, preferably in archivelog mode for a production system.