This monitoring program provides information on physical access to files on a selected disk, provided that access was by way of the privileged I/O output system PPAM. This includes file access using the methods EAM (Evanescent Access Method), ISAM (Indexed Sequential Access Method), SAM (Sequential Access Method) and UPAM (User Primary Access Method).
In the case of multiprocessor systems, monitoring is restricted to I/O operations originating in the local system running SM2.
Notes
In every monitoring cycle up to 300 file names are collected per disk. They are selected in the sequence of the first input/output within the monitoring cycle. Of the collected file names the 20 file names with the most inputs/outputs are written to the SM2 output file.
The file name must always have the format
:<catid>:<$userid>.<filename>. A different format can be used for special disk accesses (e.g. from DAB).*OVERRUNS is a reserved file name. Here all inputs/outputs which could not be assigned to a specific file are counted are counted.
If the monitoring program is used for parallel access volumes (PAV), the following applies:
Base devices and alias devices can be selected.
If a base device is selected, the data refer also to the assigned alias devices.