Overview

This report shows how much I/O time was used by each DASD (direct access storage device) or tape device for which activity was measured during the observation session. The quantification is based on the number of samples activity on the device was observed. This is expressed as a percentage of the total number of samples.

Two types of detail lines are shown:
  • Volume
  • Cylinder Address (for DASD)

Initially, only the Volume lines are visible. You can expand a Volume line (using the “+” line command) to reveal its subordinate Cylinder Address lines.

A sample report is shown here, it has been fully expanded: 

  File  View  Navigate  Help
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D01: DASD Usage Time by Device (0618/TSTJOB01)                Row 00001 of 00006
Command ===> __________________________________________________ Scroll ===> CSR 

Volume>Cyl   Unit-Dev>DD        Percent of Time * 10.00%  ±2.2%
                                    *....1....2....3....4....5....6....7....8..
BKNSM2      0A93-3390           8.90 ====
→ Cyl_00BA         VSAM1        8.85 ====
→ Cyl_0007         VSAM1        0.05

BKNSM1      0A92-3390           1.25 ==
→ Cyl_0086         INFILE       1.25 ==
Parent topic: D01 - DASD usage by device