z/OS I/O Subsystems

Objectives
On successful completion of this course, attendees will be able to:

• describe the main features of the Channel Subsystem and channel programming
• explain ESCON, ESCON directors and FICON
• describe the IOCP process
• describe the A-Z of an I/O.

Who Should Attend
IT personnel who need to understand how I/O works, and who want a clear picture of the physical infrastructure of the I/O subsystem in a z/OS environment.
Prerequisites
A general knowledge of operational concepts in mainframe installations and some understanding of MVS concepts.
Duration
1 day
Course Code
5079
Contents
I/O hardware in an IBM type mainframe complex
Types of I/O devices (disk, tape, communications, printer); Control Units and devices; Coupling Facilities (CFs); Channel Paths (CHPIDs).


The physical attachment of I/O devices
Bus and tag (copper) cables; the fiber optic ESCON link; cable assemblies and connectors; distribution panels; couplers and adapters; ESCON Directors; ESCON Converters and Channel Extenders.


Types of connections
channel to control unit (CNC, BY, BL); channel to channel (CTC); channel to CF channel (CFR, CFS); channel to FICON bridge (FCV).


Overview of how to configure the Channel Subsystem



The A-Z of an I/O operation, from application prog
The program that needs 'to do I/O'; allocating the data set; opening the data set; invoking the Access Methods (VSAM, QSAM, etc.); channel programming with Channel Command Words (CCW); going to the I/O Supervisor (IOS); 'Off it goes!' - the I/O is running...; channel program end and I/O interrupts; back-end processing.