Calculating DASD space and placement for the extract data set

Table 1 helps you calculate DASD space requirements for the extract data set specified by the REPTEXT DD statement or the XREPTEXT DD statement.

Table 1. DFSMSrmm extract data set DASD space requirements
Extract Data Set Content	DASD Space
Data sets	500 KB for every 1000 data sets when data set records are selected. 1564 KB for every 1000 data sets when extended records are selected.
Shelf locations in the library that do not contain volumes	11 KB for every 1000 shelf locations
Shelf locations in storage locations	11 KB for every 1000 shelf locations
Owners	35 KB for every 1000 volumes
Software products	17 KB for every 1000 software products
Volumes	1000 KB for every 1000 volumes when volume records are selected.
Vital record specification	20 KB for every 1000 vital record specifications

Convert the final figure into a space allocation. The extract data set has a record format of variable-length blocked records. Choose either a system-determined block size, or a block size suitable for the device your installation uses.

To calculate the space required:

The number of KB is the number to use in the space allocation.
Use a fraction of this total space as secondary space if you want to have an extract data set that extends to multiple extents.

You can use JCL as shown in Figure 1 to create the extract data set prior to running EDGHSKP.

Figure 1. JCL for specifying the extract data set

//REPTEXT DD DISP=(NEW,CATLG),DSN=RMM.EXTRACT.DSET,
//        RECFM=VB,BLKSIZE=0,
//        UNIT=SYSALLDA,AVGREC=U,SPACE=(1024,(pp,ss))

where:

pp: Specifies the calculated primary space.
ss: Specifies a fraction used for secondary space.