DFSMShsm processes user data sets during automatic backup processing with only one buffer because some sites with heavy processing loads have experienced storage constraints with multiple buffers. Depending on the DFSMShsm configuration at a site, the number of buffers for automatic backup processing may be increased without any storage constraints. You can control the number of buffers that DFSMShsm uses for backup and migration with the following PATCH command:

 PATCH .MCVT.+391 X'nn'VERIFY(.MCVT.+391 X'00')  /* Change the default number*/ 
                                                 /* of buffers for backup and*/
                                                 /* migration of data sets   */