JES3plus I/O Improvements
Project and Program: MVS
, MVS Performance
, SHARE Dallas 2022
Since its initial release in April 2020, JES3plus has been steadily enhanced to provide superior I/O performance characteristics.
IBM's existing ECKD (Enhanced Count-Key-Data) I/O was first improved to use ACKD (Advanced CKD) I/O. Later, zHPF (IBM Z High Performance FICON) support was implemented and delivered to customers.
The speaker will provide some high-level background on the evolution of mainframe DASD I/O, from the early days of the bus & tag cables to what we use today. He will then take us through a detailed explanation of what was changed in JES3plus SPOOL I/O and why those changes perform better than the original ECKD I/O implementation.
Some performance results will be shared to put things into perspective and a "sneak" preview of additional, not-yet-released I/O improvements will be provided.
Back to Proceedings File Library