Virtual machine storage policies are essential to virtual machine provisioning. These policies help you define storage requirements for the virtual machine and control which type of storage is provided for the virtual machine, how the virtual machine is placed within the storage, and which data services are offered for the virtual machine.
When you define a storage policy, you specify storage requirements for applications that run on virtual machines. After you apply this storage policy to a virtual machine, the virtual machine is placed in a specific datastore that can satisfy the storage requirements. In software-defined storage environments, such as Virtual SAN and Virtual Volumes, the storage policy also determines how the virtual machine storage objects are provisioned and allocated within the storage resource to guarantee the required level of service. In environments with third-party I/O filters installed, you can use storage policies to enable an additional level of data services, such as caching and replication, for virtual disks.