Freezing Posts Before Upgrade

[ctrl-alt-del]

I'm going to perform a database migration / upgrade to a new system. Is there an easy way to freeze all posting activity on a forum so that everything is essentially read-only with no permissions to write?

[Zachery]

Turning the forums off is generally a good idea, though thats not so much a freeze. I'd suggest turning the forums off, doing a backup, and then chaging the permissions on the registered usergroup to not be able to post new threads/posts.

[ctrl-alt-del]

Thanks. That answer suffices. Modifying the usergroups to prevent posting will be much easier than modifying the forums to disable posting.