Get the Whitepaper called Using Metasploit With Nessus Bridge On Ubuntu. The author discusses using the autopwn feature in Metasploit, running Nessus from within Metasploit, choices of databases to use, and the benefits of each.
You can download it from the following link: https://packetstormsecurity.com/files/download/103105/Metasploit_nessus_bridge.pdf
Source: https://packetstormsecurity.com/files/103105/Using-Metasploit-With-Nessus-Bridge-On-Ubuntu.html