To back up tape, use NOCOPY mode, which you request by specifying NOCOPY for the MODE option with the FlashCopy® establish request. NOCOPY mode generates a logical copy of source data that can be read from another device (the target). This allows read activity (from the target device) to be separate from application read/write activity on the source device. A backup program like DFSMSdss can use the target device as input for backing up data to tape. If you need a physical copy of the source data, you can use the FlashCopy COPY mode. While the physical copy is taking place, the backup program can copy target data to tape.