As of level 0234-00, BSA supports concurrent copy. This means that you can create a backup of the BQL database while the started task is running.
To back up the BQL database while the started task is running requires the concurrent copy function of DFSMS/z/OS (available as of DFSMS/z/OS V1R1) or equivalent functions if you are using non-IBM products.
For more information, see "Using concurrent copy to back up a running BQL database" in BSA Installation and System Guide.
For detailed information on hardware requirements, see the IBM publication Implementing Concurrent Copy if you are using DFSMS/z/OS. If you are using a non-IBM product, see the documentation of this product.