Example

Consider the following example to help you choose between FILESYSTEM and FILEIMAGE.

Take-up is run against two daily SMF files for Image MVS1:
  1. DAILY.SMF(0) contains data for CICS® systems CICS1 and CICS2
  2. DAILY.SMF(-1) contains data for CICS systems CICS2 and CICS3

The SYSTEMS option will define the three CICS systems: CICS1, CICS2 and CICS3, and one image MVS1.

FILEIMAGE defines both SMF files to image MVS1. All three CICS systems are eligible to use both files because each system belongs to image MVS1. The drawback is that CICS3 has no data on generation 0, and CICS1 has no data on generation –1. But at report submission time, CICS PA has no way of knowing which image file has data for the selected system, so both files are selected. For example, reporting against CICS1 will select both files, even though generation –1 contains no relevant data.

FILESYSTEM defines the SMF file to image MVS1, and also defines it to each CICS system that has data on the file. CICS1 has one daily SMF file definition only, generation 0. Now at report submission time, CICS PA will select only generation 0. The drawback is that the file is defined to multiple systems. But this is not really a problem because daily SMF file maintenance is handled automatically by HDB housekeeping which deletes expired daily SMF file definitions, and the dialog itself which ignores expired daily SMF files.