The SDBGENR option specifies whether system-determined block size should be used to set an optimal block size for SYSUT2 data sets in BetterGener applications when no block size is provided. This parameter will automatically provide a block size that will most efficiently utilize the space on the output device.
See the SDB option for a description of the parameters, substituting SYSUT1 for SORTIN and SYSUT2 for SORTOUT in the description.