Front cover Introduction to the New Mainframe: z/OS Basics An introduction to mainframe computing on the IBM zSeries platform z/OS concepts and facilities for students and beginners zSeries hardware and peripheral devices Mike Ebbers Wayne O’Brien Bill Ogden ibm.com/ International Technical Support Organization z/OS Basics March 2005 SG24-6366-00 Note: Before using this information and the product it supports, read the information in “Notices” on page -1. First Edition (March 2005) © Copyright International Business Machines Corporation 2005. All rights reserved. Note to U.S. Government Users Restricted Rights -- Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp. Contents Preface . xvii How this text is organized . xvii How each chapter is organized . xviii Acknowledgements . xix Comments welcome. xxi Part 1. Introduction to z/OS and the mainframe environment Chapter 1. Introduction to the new mainframe . 1-1 1.1 The new mainframe. 1-2 1.2 Evolving architecture . 1-2 1.3 Mainframes in our midst . 1-4 1.4 What is a mainframe? . 1-5 1.5 Who uses mainframe computers?. 1-7 1.6 Factors contributing to mainframe use . 1-8 1.6.1 Reliability, availability, and serviceability. 1-9 1.6.2 Security . 1-10 1.6.3 Scalability . 1-10 1.6.4 Continuing compatibility . 1-11 1.7 Typical mainframe workloads . 1-11 1.7.1 Batch processing. 1-12 1.7.2 Online transactional processing . 1-15 1.8 Roles in the mainframe world . 1-17 1.8.1 Who is the system programmer? . 1-19 1.8.2 Who is the system administrator? . 1-20 1.8.3 Who are the application designers and programmers? . 1-21 1.8.4 Who is the system operator? . 1-21 1.8.5 Who is the production control analyst? . 1-22 1.8.6 What role do vendors play? . 1-22 1.9 z/OS and other mainframe operating systems . 1-23 1.9.1 z/VM . 1-24 1.9.2 VSE . 1-24 1.9.3 Linux for zSeries . 1-24 1.9.4 z/TPF. 1-25 1.10 Summary . 1-26 1.11 Topics for further discussion . 1-27 Chapter 2. z/OS overview. 2-1 2.1 What is an operating system? . 2-2 © Copyright IBM Corp. 2005. All rights reserved. iii 2.2 What is z/OS? . 2-2 2.2.1 Hardware resources used by z/OS . 2-3 2.2.2 Modules and macros. 2-4 2.2.3 Program status word . 2-5 2.2.4 Multiprogramming and multiprocessing . 2-5 2.2.5 Control blocks . 2-6 2.2.6 Physical storage used by z/OS . 2-6 2.3 Virtual storage and other mainframe concepts . 2-7 2.3.1 What is virtual storage?. 2-7 2.3.2 What is an address space?. 2-8 2.4 Virtual storage overview . 2-9 2.4.1 What is paging? . 2-9 2.4.2 What is a virtual storage address? . 2-10 2.4.3 What is dynamic address translation? . 2-11 2.4.4 How does virtual storage work? . 2-12 2.4.5 Frames, pages, and slots . 2-13 2.4.6 Page stealing . 2-14 2.4.7 Swapping . 2-14 2.4.8 A brief history of virtual storage and 64-bit addressability. 2-15 2.4.9 What’s in an address space? . 2-19 2.4.10 z/OS system address spaces . 2-20 2.5 How peripheral storage is managed in z/OS. 2-21 2.6 Summary of z/OS facilities . 2-22 2.7 Defining characteristics of z/OS . 2-23 2.8 Program products for z/OS . 2-24 2.9 Middleware for z/OS . 2-25 2.10 Interfaces for z/OS application programmers . 2-26 2.11 A brief comparison of z/OS and UNIX. 2-26 2.12 Summary . 2-29 2.13 Questions for review . 2-30 2.14 Topics for further discussion . 2-31 Chapter 3. TSO/E, ISPF, and UNIX: Interactive facilities of z/OS . 3-1 3.1 How do we interact with z/OS? . 3-2 3.2 TSO overview . 3-2 3.2.1 Using TSO commands in native mode . 3-3 3.2.2 Using CLISTs and REXX under TSO . 3-6 3.3 ISPF overview . 3-6 3.3.1 Keyboard mapping used in this course . 3-12 3.3.2 Using PF1-HELP and the ISPF tutorial . 3-13 3.3.3 Navigating through ISPF menus . 3-14 3.3.4 Using the ISPF editor . 3-17 3.3.5 Using the online help. 3-18 iv z/OS Basics 3.3.6 Customizing your ISPF settings . 3-20 3.3.7 Adding a GUI to ISPF . 3-23 3.4 z/OS UNIX interactive interfaces. 3-24 3.4.1 ISHELL command (ish) . 3-26 3.4.2 ISHELL - user files and directories . 3-26 3.4.3 OMVS command shell session . 3-27 3.4.4 Direct login to the shell . 3-28 3.5 Summary . 3-30 3.6 Questions for review . 3-31 3.7 Exercises. 3-32 3.7.1 Logging on to z/OS and entering TSO commands . 3-32 3.7.2 Navigating through the ISPF menu options . 3-32 3.7.3 Using the ISPF editor . 3-33 3.7.4 Using SDSF . 3-34 3.7.5 Opening the z/OS UNIX shell and entering commands . 3-35 3.7.6 Using the OEDIT and OBROWSE commands . ..