Architecting a vCloud Director Solution : vCloud Director Design : 7.3 Organization Virtual Data Centers : 7.3.3 Pay-As-You-Go VDC
   
7.3.3 Pay-As-You-Go VDC
Pay-as-you-go VDC provides instant committed capacity on demand. Resources (vCPU, memory and storage) are committed only when virtual machines or vApps are instantiated within the VDC. The tenant is charged only based on the committed resources (CPU and memory for powered-on VMs, storage for deployed VMs).
Set limits on the maximum size of the VDC to prevent a sudden spike of resource usage of one customer which would prevent other tenants from deploying new VMs.