Disk I/O

The following reports can be used for monitoring disk I/O:

JREPORT 004 shows the average number of I/Os to disk for a given program.
DCMT DISPLAY RUN UNITS or OPER W DB RU shows if any run units are waiting for a journal buffer (as indicated by a run unit status value of IUH). IUHs occur most frequently when the fast mode threshold is set too low.

For information on the JREPORTS (journal reports), refer to the CA IDMS Reports Guide.