> I work at an ISP and we're going to put a mysql-cluster in production
> as our Freeradius backend, as you know the radius database always keeps
> growing because of the accounting, and I want to estimate the maximum
> size it could reach, how can I know how much my cluster can store?
I may recommend you to make multilevel accounting archive (we do). Store
active sessions in Cluster and after they close, move them to archive
(presumably partitioned InnoDB). Of course, this will require some
modifications to billing/accounting/tech systems to select data from both
the Cluster and archive, but it's worth the effort.