SVTSSP - Subsystem Performance Request File

At the DETAIL timespan, the Subsystem Performance Request File provides statistics on VTSS performance and is derived from the VTSS user SMF record, subtype 10, 'VTSS Subsystem Performance'.
micsrm140
This record is produced on an interval basis, typically every 15 minutes. VTSS disk buffer usage statistics are contained this file.

File Organization

The table below identifies data elements by which the file is sequenced and summarized in each timespan. N/A indicates that the file is not supported in a timespan. At the DETAIL level, data is sequenced but not summarized.
The timespans in which a file is supported are defined by each installation when
MICS
is installed. Therefore, this table has been generated as part of the installation process to accurately reflect the
MICS
system at your installation.
SVTSSP Sort Sequence and Data Granularity
+---------+-------------------------------------------------+ |Timespan | Level of Data Granularity | +---------+-------------------------------------------------+ | | | | DETAIL |SYSID VTSSID YEAR MONTH DAY | | |HOUR ENDTS | | | | | DAYS |SYSID VTSSID YEAR MONTH DAY | | |HOUR | | | | | WEEKS |SYSID VTSSID YEAR WEEK ZONE | | |HOUR | | | | | MONTHS |SYSID VTSSID YEAR MONTH ZONE | | | | | YEARS | N/A | | | | +---------+-------------------------------------------------+ | TABLES | N/A | +---------+-------------------------------------------------+ Generation Date: Tue, May 12, 2009
This file was generated with ESSENTIAL=ALL option in effect. All data elements that are defined in the file are generated.
This file was generated with DERIVED=DEFault option in effect. The complex definition of the DERIVED option controls whether the data elements are kept on the file on auxiliary storage.

Data Elements List

The following table identifies data elements contained in this file.
GENERATION DATE: Tue, May 12, 2009 Note: Essential data elements are identified by an "E" under the Timespan asterisk (*) column. Time- Data Data Element Span * Element Description (LABEL) ------- -------- ---------------------------------------- Sequence/Summary Data Elements XD....E DAY - Day of Month XDW...E HOUR - Hour of Day XD.M..E MONTH - Month of Year XDWM..E SYSID - System Identifier XDWM..E VTSSID - VTSS ID XDW...E WEEK - Week of Year XDWM..E YEAR - Year of Century XDWM..E ZONE - Time Zone Common Data Elements XD....E DAYNAME - Name of Day of Week XDWM..E DURATION - Recording Interval Time XDWM..E ENDTS - End Time Stamp XDWM..E INTERVLS - Number of Recording Intervals XDWM..E ORGSYSID - Originating System Identification XDWM..E STARTTS - Start Time Stamp Accumulated Data Elements XDWM..E SSPBCH - Base Cache Size (MB) XDWM..E SSPBRP - GB Read for Free Space Collection (GB) XDWM..E SSPCCH - Customer Cache Size (MB) XDWM..E SSPCDP - Standard Capacity Defined (GB) XDWM..E SSPCFP - Collected Free Disk Buf. Capacity (GB) XDWM..E SSPCOUNT - Subsystem Performance Record Count XDWM..E SSPEBC - ECAM-T Msgs. Bypassed (Config Busy) XDWM..E SSPEBS - ECAM-T Msgs. Bypassed (No Buffer) XDWM..E SSPECP - Total ECAM-T Channel Programs XDWM..E SSPEMP - Total ECAM-T Messages Processed XDWM..E SSPFCP - Total Free Disk Buffer Capacity (GB) XDWM..E SSPNSZ - NVS Size (MB) XDWM..E SSPOCH - Offline Cache Size XDWM..E SSPPCH - Pinned Cache Size XDWM..E SSPRGC - Redundancy Group Count XDWM..E SSPSCP - Total Free Space Collection (GB) XDWM..E SSPTCP - Total Disk Buffer Capacity (GB) XDWM..E SSPUCP - Total Used Disk Buffer Capacity (GB) Derived Data Elements XDWM..E SSPAVBRP - Avg Bytes Read for Free Space (GB) XDWM..E SSPAVCDP - Avg Defined Capacity (GB) XDWM..E SSPAVCFP - Avg Collected Free Disk Buffer (GB) XDWM..E SSPAVFCP - Avg Free Disk Buffer Capacity (GB) XDWM..E SSPAVSCP - Avg Free Space Collected (GB) XDWM..E SSPAVTCP - Avg Disk Buffer Capacity (GB) XDWM..E SSPAVUCP - Avg Used Disk Buffer Capacity (GB) XDWM..E SSPPCFCP - Pct Free Disk Buffer Capacity XDWM..E SSPPCUCP - Pct Used Disk Buffer Capacity
For a detailed description of individual data dictionary elements, see VTSS Subsystem Performance File (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. Because 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.

Retrieval Examples

In the examples, a SAS macro variable is used to specify the DDname part of the
MICS
file name. These macro variables are a standard part of
MICS
and are available for all files. The macro variable name has the form &diiit, where d is the database identifier, iii is the information area name, and t is the timespan. For the examples, a database identifier of P is used. The identifier is installation-dependent, so you should find out what the identifiers are at your installation.
  • Generate a plot chart of virtual tape disk buffer usage throughout the previous day for each SYSID/VTSSID combination. The chart displays the total disk buffer capacity in the VTSS, and the amount used throughout the day.
    PROC PLOT DATA=&pSVTd..SVTSSP01; PLOT SSPAVTCP*HOUR='*' SSPAVUCP*HOUR='=' / OVERLAY; BY SYSID VTSSID; LABEL SSPAVTCP='Total Disk Buffer Capacity'; LABEL SSPAVUCP='Used Disk Buffer Capacity'; TITLE 'Virtual Tape Storage Subsystem'; TITLE2 'Total Capacity vs Usage';
    Note:
    For VTSSs that are shared among various SYSIDs, the plot will have a similar pattern for the same VTSS, because the subtype 10 interval record for each SYSID will have a snapshot view of the VTSS cache status at that point in time. Pick one SYSID as the reporting SYSID for each VTSS. Summarizing data across SYSIDs for the same VTSS will result in inflated values.
  • Generate a plot chart of virtual tape disk buffer usage throughout the previous day by hour, summarized for each VTSSID. The chart displays the total disk buffer capacity in the VTSS, and the amount used throughout the day by hour. No matter how many SYSIDs have the VTSS as a shared resource, this provides the view from the VTSS.
    PROC MEANS DATA=&PSVTX..SVTSSP01 NONOBS NWAY NOPRINT; CLASS VTSSID HOUR; VAR SSPTCP SSPFCP SSPUCP; OUTPUT OUT=TEMP MEAN = TOTAL FREE USED; RUN; PROC PLOT DATA=TEMP; PLOT TOTAL*HOUR='*' FREE*HOUR='=' USED*HOUR='@' / OVERLAY; BY VTSSID; TITLE1 'VIRTUAL TAPE STORAGE SUBSYSTEM'; TITLE2 'Capacity vs Usage by hour'; RUN; PROC SORT DATA=TEMP; BY VTSSID HOUR; RUN; PROC PRINT DATA=TEMP NOOBS SPLIT='*'; VAR VTSSID HOUR TOTAL USED FREE; LABEL VTSSID = 'VTSS*NAME' TOTAL = 'Backend*Capacity(GB)' FREE = 'Free*Backend*Capacity(GB)' USED = 'Used*Backend*Capacity(GB)' ; FORMAT TOTAL COMMA9.; FORMAT FREE COMMA9.; FORMAT USED COMMA9.; TITLE1 "Virtual Tape Storage Subsystem"; TITLE2 "Backend Capacity Usage"; RUN;