MySQL Quota
As is users may have a database (soon they might have more than one). This database(s) can - at the present - have literally unlimited space. There should be a quota system in place that keeps track of the MySQL database size for this Vsite.
If a Vsite has a total database size that exceeds a predefined quota, then the database(s) should either get set read only, or the MySQL access for that Vsite should get disabled.
This needs to tie into Active Monitor to send warning emails when approaching threshold or when a “Red” action is taken. Additionally this needs to get tied into the Reseller management, so that a Reseller might have X GB of MySQL database tables that he can distribute between Vsites. If that limit gets exceeded, action is taken, too.