[Zope] Read-only mode for Zope 2.8.6?

[Dan Gaibel]

Happy new year, Zope gurus!

I am migrating to a new server and I'd like to be able to put the old machine into a read-only mode so that no new transactions occur as I transfer data over. In zope.conf there is a "read-only-database"  directive, which I set to "on" and it has no effect (I can still make changes.) Is there an easy way to make the database inaccessible for updating?

Many thanks,

Dan