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For releases prior to Version 1, if your S2KPADnn file is allocated on a single volume, set the PADnn= parameter to YES. SYSTEM 2000 software calculates the number of allocation units and the number of blocks per allocation unit.
For a multi-volume file, you must calculate the parameter values for PADnn= number of units to allocate / number of blocks in each unit. Below is an example of a DD statement for an S2KPADnn file that spans multiple volumes:
//S2KPADnn DD UNIT=SYSDA,VOL=SER=(DISK01,DISK02), // SPACE=(CYL,(100,50))
This allows 100 cylinders for primary allocation and 15 times 50 cylinders for secondary allocation. 100 cylinders primary + 750 cylinders secondary totals 850 cylinders for the first volume, and 50 cylinders times 16 extents for a total of 800 cylinders for the second volume.
If the device used in the above example is a 3390 and the blocksize for S2KPADnn is 27,360 bytes:
1) number of blocks per track: 2
2) total number of tracks: 1650 cylinders * 15 tracks per cylinder = 24750 tracks
In the example PADnn=24750/2, one track of space on the S2KPADnn file is used 24,750 times. In the example PADnn=1650/30, one cylinder of space on the S2KPADnn file is used 1650 times.
The maximum number of addressable tracks for an S2KPADnn file is 65,535.