IOA Access Method file allocation formulas

The following formulas illustrate how to calculate space requirements for the Control‑D Repository. For simplicity, only User Report and $SYSDATA record types are taken into account.

To calculate the number of blocks needed to allocate IOA Access Method file data and index components of the Active User Report file, use the formula:

NumberOfBlocks = [(MaxRpts * AvgRptLrecl) + (MaxRpts * AvgSysdataLrecl * RecRatio)]* 1.5/Blksize

To calculate the number of cylinders from the resulting number of blocks, use the formula:

NumberOfCylinders = [NumberOfBlocks/BlocksPerTrack]/TracksPerCylinder + 1

where

• MaxRpts is the maximum number of User Report records to be retained.
• AvgRptLrecl is the average User Report record size.
• AvgSysdataLrecl is the average $SYSDATA record size.
• RecRatio is the ratio of $SYSDATA records to User Report records.
• BlocksPerTrack is the number of blocks per track according to block size and track size.
• TracksPerCylinder is the number of tracks per cylinder according to the specific device type.

The following table provides other relevant information for your convenience:

Table 82 Relevant device information