Hi Josh
Currently 6.5TB across 7 stores on the Hitachi SAN, and 3 x 1TB stores on a standalone EQL to be migrated. So to stand still and just migrate what I have, I would need 9 x 1TB Datastores.
I suppose I could have bigger datastores, assuming there aren't hard or performance limits to number of VMs per datastore?
Re. ESXi 5.0 / 5.1 I have only just upgraded vcenter to 5.0, I still need to upgrade the hosts to 5.0. As part of that upgrade I migrated vCenter + SQL DB from a phys server to a vm, so upgrades aren't as scary now. 5.0 will be sufficient for now to take advantage of the storage APIs etc for the new EQL SAN (I think...)