The Legac-e Information Site
Legac-e - BLKSIZE : Relevance to Performance and Capacity
Why BLKSIZE=32720 is bad
Remember that z/OS does not know anything about modern disk subsystems, so al its disk space calculations are based on the premise that 1990s technology disks are being used and if thet are defined as 3390s the logical track capacity is 56,664 bytes.