The pd_prf_file_count operand of the system definition specifies the number of generations of performance trace information files (the default value is 15) that are created under the following directory:

$PDDIR/spool/pdprf/file-name

The file name is created as pdprf_generation-number. For example, a file with a generation number of 1 is pdprf_001. If the performance trace information being output does not fit within the file size specified by the pd_prf_file_size operand of the system definition (default value: 51,200 kilobytes), the output destination is swapped to the next file. If the file in the last generation becomes full, the output destination is swapped to the first file and this file is overwritten.

You can use the pd_prf_output_directory operand to change the PRF trace output directory.