4. FILES › 5.2 VTS Component Files › 5.2.3 VTS Component SVT Information Area Files › 5.2.3.2 Subsystem Performance Request File(SVTSSP) › 5.2.3.2.3 SVTSSP Usage Considerations

5.2.3.2.3 SVTSSP Usage Considerations

The disk buffer capacity metrics are accumulated at higher
timespans.  The values must be divided by the intervals to
obtain the real values.  Average elements have already been
provided in the file for this reason.  For example, using
SSPTCP, Total Disk Buffer Capacity reporting on disk buffer
usage with SSPTCP (Total Disk Buffer Capacity) and SSPUCP
(Used Disk Buffer Capacity), at higher timespans will display
highly inflated numbers.  Using the SSPAVTCP and SSPAVUCP
will display the average total and average used disk buffer
capacity, and will reflect reality.

When multiple z/OS hosts share a VTSS, reporting can be done
by subsetting to one of the hosts to get an accurate picture
of VTSS capacity usage.  Since this file is created from
interval records the statistics are as of the time the SMF
record was produced for the VTSS.  If 4 hosts share a VTSS,
the timestamps on the StorageTek User SMF record, subtype 10,
will vary from host to host, sometimes minutes apart.  Thus
this record is a global view of the VTSS at that point in
time.