About control of the storage
The vendor's storage implementation controls the storage format and where the images reside on the storage. The vendor controls the data transfer method. Consequently, performance and storage utilization are highly optimized.
NetBackup has no knowledge of how the backup images are stored. Also, Veritas does not control which capabilities the vendor exposes through the OpenStorage API. Similarly, Veritas and NetBackup have no control over the communication between the vendor plug-in and the storage server. The vendor determines the API or protocol to use between the plug-in and the storage server.
NetBackup determines when backup images are created, copied, or deleted. Images cannot be moved, expired, or deleted on the storage unless NetBackup instructs the appliance to do so through the API.