The supported backup procedure is documented in the readme.htm which is in the documents directory on Unity disk 1. You will discover that the only qualified backup product is BackupExec.
The issue that I see you having is that BackupExec is not supported to run on the CallManager. You will need to backup to a machine other than the CM.
Keith
Keith Chambers
Unity Technical Lead
Unified Voice Team, San Jose
Cisco Systems
kechambe@cisco.com