This property appears for master servers only, but applies to all media servers as well. This property does not apply to NDMP drives.

If a client is also a media server or a master server and Must use local drive is checked, a local drive is used to back up the client. If all drives are down, another can be used.

This property increases performance because backups are done locally rather than sent across the network. For example, in a SAN environment a storage unit can be created for each SAN media server. Then, the media server clients may be mixed with other clients in a policy that uses ANY AVAILABLE storage unit. When a backup starts for a client that is a SAN media server, the backups go to the SAN connected drives on that server.