7.1 Provider Virtual Data Centers
The virtual data center (VDC) is the standard container for a pool of compute, storage and network resources. There are two types of virtual data centers—provider and organization. Provider virtual data centers are assembled from resource pools and datastores represented by storage policies managed by a single resource group vCenter Server.
A provider VDC can span multiple resource pools (or dedicated clusters) and form elastic organization VDCs. However, this is supported only for pay-as-you-go Org VDCs and for Allocation Pool VDCs. Reservation pool VDCs are never elastic and are constrained by the size of the primary resource pool (cluster) of the provider VDC.
Note The vCloud administrator must enable elastic allocation pool VDCs. This is a system-wide setting.
The following are provider virtual data center design considerations:
• Mixing organization VDC allocation types within the provider VDC is possible, but complicates capacity management, particularly when different allocation types have different performance SLAs.
• From a manageability perspective, VMware recommends backing the provider VDC with vSphere clusters. It is also possible to divide a cluster into multiple resource pools and assign these to different provider VDCs. This might be useful when non-vCloud Director managed VMs are deployed into the same cluster. In this case, manually set resource pool limits so vCloud Director understands the amount of resources each provider VDC can consume from the subdivided vSphere cluster.
• Each availability zone must have its own provider VDCs. This allows creation of site-specific Org VDCs.
• Create dedicated Org VDCs on top of a customer-dedicated cluster in a customer-dedicated provider VDC.
• Elastic provider VDCs allow seamless expansion (and possible migrations) for allocation and pay-as-you-go Org VDCs.
• A VXLAN network pool from which organization VDC and vApp networks are provisioned is created automatically with the creation of each provider VDC. Each VXLAN network pool is represented by VXLAN network scope spanning clusters that belong to a given provider VDC. An organization VDC can use any network pool (but only one).
• Host preparation does not push the vCloud agent to the ESXi host provided that no vCloud Director Network Isolation (VCDNI)-backed network pools are defined. However, it sets specific custom attribute to control host – VM compatibility.