Monitoring I/O activity of data sets

IFCID 0199 provides information such as the average write I/O delay or the maximum delay for a particular data set over the last statistics reporting interval. The same information is also reported in the DISPLAY BUFFERPOOL command with the LSTATS option. Furthermore, IBM® OMEGAMON® for Db2 Performance Expert on z/OS® reports IFCID 0199 in batch reports and in online monitoring.

More detailed information is available, with more overhead, with the I/O trace (performance class 4). If you want information about I/O activity to the log and BSDS data sets, use performance class 5.

You can also use RMF to monitor data set activity. SMF record type 42-6 provides activity information and response information for a data set over a time interval. These time intervals include the components of I/O time, such as I/O disconnect time.Using RMF incurs about the same overhead as statistics class 8.