To enable efficient storage operations in vCloud Director, even at scale, when maintaining thousands of vApp workloads, vSAN uses a Storage Policy-Based Management (SPBM) framework.

Storage Policy-Based Management is the foundation of the VMware software-defined storage model control plane, and enables vCloud administrators to overcome a number of storage provisioning challenges, such as capacity planning, differentiated service levels, and maintaining capacity headroom.

By defining storage policies through vCloud Director, SPBM can optimize the vApp provisioning process and leverage the vSphere Storage Policy-Based Management API to automate storage management operations for the software-defined storage infrastructure.

By default, the *(Any) storage policy is created and employed by vCloud Director. However, do not employ the *(Any) policy, which is provided for compatibility reasons only. If the design requires storage tiering within an elastic VDC as described in Model 2, vCloud administrators must use the storage policies leveraged from vCenter Server to place a vApp on a specific storage policy within vCloud Director achieved through the use of tagging rules.

After the datastore storage capabilities are configured, the storage policies must first be created in vSphere. These policies are then automatically presented to vCloud Director where they can be viewed within the Provider VDC. These storage policies define the quality of storage that the VM disks reside on, and therefore, must be mapped to the datastores that have been classified.

By default, a storage policy is set when the Org VDC is created, which means that when provisioned by a vApp Author, all virtual machines, unless otherwise specified, utilize that storage policy, and therefore be located on that tier of storage. However, by using this architecture, where a three-tier vApp is required to be deployed, each individual virtual machine within the vApp can have its own storage policy, with the storage policies being specified individually when the vApp is provisioned.

As a result, compliance and deployment of multi-tier applications can be achieved through SPBM. Furthermore, using SPBM in this way through vCloud Director allows the provisioning in an on-demand basis, reducing the burden of storage administrators and empowering the vCloud consumers and vApp authors to take responsibility for vApps and automated provisioning tasks.

This architecture enables the vApp authors to tier the individual virtual machines in their vApps, as required by the application, in each Org VDC. This is made possible by the tiered storage resources available within the single elastic Provider VDC. In addition, the storage policy of a virtual machine can also be changed at any time. By changing the storage policy of the virtual machine, the virtual machine and each of its VMDK files will be migrated to a cluster and datastore which is compliant with the selected storage policy.

VMware vCenter Chargeback Manager™ integrates with the storage policy features presented to vCloud Director from vCenter Server, and can be employed to accurately identify and track storage policies utilized by virtual machines. This makes it possible to meter vCloud consumers based on the virtual machine storage policy, or classification of the storage on which the virtual machine resides.