3. Choosing a vCloud Consumption Model : 3.2 vCloud Director Allocation Models : 3.2.4 Storage Allocation
3.2.4 Storage Allocation
The allocation of storage resources is the same for all allocation models and is charged as capacity is allocated. The vCloud provider manages storage resource overcommitment by defining a maximum amount of storage that can be consumed within the organization virtual datacenter and by controlling whether storage is thin-provisioned (not pre-allocated) or thick-provisioned (pre-allocated in full).
A vCloud Director 5.1 feature provides multiple classes or tiers of storage capacity within an organization virtual datacenter. This allows an application owner to deploy a multitier application with different classes of storage for different tiers.