How to improve archive performance

Hi, I need to backup an OnLine (version 5.0) with large databases. The OnLine does not use transaction logging. Because an archive does not fit in one tape it is necessary to do the archive when someone is at the console and can change the tape. I was thinking in doing an archive (level 0) just once and after that during the night (from contrab) run a tbunload of each database that can fit in one tape. Is that right? What would happened in case of a system crash? I mean, can I restore the entire system using the level 0 archive plus the tbunloads? The tables in the databases are heavily used so an incremental backup would take several tapes as well. Thank you very much. Please e-mail to me. Agostino Brunamontini SRD. Italy. abrunamontini@srd.it