VSAM KSDS buffers

If the database data set is a VSAM KSDS, you can specify the AMP operand in the data set’s DD statement. You can also specify the BUFNI/BUFND or BUFSP subparameters of AMP. The Unload function honors the user-specified values if they are adequate. The Unload function uses BUFNI=16 and calculates the minimum BUFND value to be equal to the number of CIs in a cylinder plus one. These values control the size of the VSAM buffer pool for the data set unless you specified larger values.