Without a doubt, observing your snapshots is the best way to estimate (roughly) what your replicas will look like.  I've been asking for a feature that would help you analyze this during a sample period, but nothing has come of it yet.
hi there, Does anyone know how to measure the amount of data that changes on an Equallogic SAN over a period of time - i.e. the change rate? I've been looking at SAN HQ but can't see this info anywhere. Cheers for any help, Huw
change rate