I/O Facility Utilization Summary report

The I/O Facility Utilization Summary report shows, by device and volume, the percentage of run time used accessing each data set. The report identifies devices by unit number and device type, volumes by serial number, and data sets by ddname. It shows index and data components of VSAM data sets separately. This report helps you to analyze file access activity.

I/O Facility Utilization Summary Report

For each device and volume, Strobe combines open and close operations under the pseudo-activity identifier .FILEMGT. Entries are ordered by unit number, volume identifier, and ddname. The report gives subtotals for each unit that has more than one entry.

UNIT NO

The address of the device accessed by the application.

DEVICE TYPE

The type of device and for DASD devices, its model number.

C	Communication
DA	Direct access
G	Graphic
MT	Magnetic tape
UR	Unit record

RUN TIME PERCENT

The percentage of total run time that the unit/volume/DDNAME combination used. There are two measures of run time:

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  • SOLO shows activity with neither concurrent CPU execution nor any other concurrent I/O activity.
  • TOTAL shows activity with or without concurrent CPU execution or other I/O activity.

RUN TIME HISTOGRAM

The intensity of activity within each unit/volume/DDNAME combination. The symbol * indicates solo usage of the device. The symbol + indicates the remaining non-solo usage. Spikes, or lengthy lines in the histogram, draw your attention to DDNAMEs with a high proportion of activity.

MARGIN OF ERROR

The margin of error for run-time percentages. This percentage is the same value that appears in the RUN MARGIN OF ERROR PCT field on the Measurement Session Data report.

% OF OBSERVED I/O WITH PAV/HPAV

The percentage of activity attributed to the device that occurred with allocated Parallel Access Volumes (PAVs). PAV indicates Static or WLM managed PAVs, and HPAV indicates activity associated with HyperPAVs.