You should back up the closed partitions and the ready partitions of a Vault Store in separate policies. In addition, these partitions do not need to be backed up daily. You can schedule these backups to occur less frequently than a directory database, for example.
If the amount of data is small enough, you can combine the closed and the ready partitions of multiple Vault Store's in a single policy. However, if the amount of data is large, Symantec recommends that you back up the closed and the ready partitions in separate policies.