If you are interested in the I/O counts and timing of your z/VSE workload, you can use one of the performance monitors provided by vendors. If you just want to see a snapshot of the counters, you may be interested in the output of the Attention Routine command "SIR SMF".
SIR SMF retrieves I/O information from the channel subsystem or the z/VSE Supervisor itself. You may use the output, e.g. to analyze performance issues. SIR SMF provides the total I/O count, average z/VSE queuing time, the average time to complete an I/O,... [More]