By default, concurrent copy for volume dumps is disabled. To enable concurrent copy for volumes dumps, DFSMShsm will request that DFSMSdss use concurrent copy, use the VOLUMEDUMP parameter of the SETSYS command.
SETSYS VOLUMEDUMP(NOCC)
For more information about using the VOLUMEDUMP parameter of the SETSYS command, see SETSYS command: Establishing or changing the values of DFSMShsm control parameters.