Mailman virtual-mailman.db

[Vizion]

I am missing something in facilitating the creation of virtual-mailman.db.

I get the failure line in maillog

fatal: open database /usr/local/mailman/data/virtual-mailman.db

I have gonne through the docs but am obviously missing something.

Could anyone please let me know:
1. How virtual-mailman.db is created
2. Ideally some examples from relevant config files would be ideal.

I do seem to ne struggling with mailman!!!

Thanks in advance

David