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4.2.2 Data Facility Storage Management Subsystem (DFSMS) . . . . . . . . 824.2.3 Auditing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 854.2.4 Resource Recovery Services (RRS) . . . . . . . . . . . . . . . . . . . . . . . . . 854.2.5 Data backup and recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 874.2.6 Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 904.3 Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 914.3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 914.3.2 U.S. Government certification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 924.3.3 Enforced isolation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 934.3.4 The accessor environment element . . . . . . . . . . . . . . . . . . . . . . . . . 934.3.5 Authorized program facility (APF) . . . . . . . . . . . . . . . . . . . . . . . . . . . 934.3.6 Program states . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 944.3.7 Storage protection keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 944.3.8 Supervisor call. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 954.3.9 System Authorization Facility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 954.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 964.5 Questions for review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 974.6 Instructor notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 994.6.1 Additional material on Auditing: Auditing in an era of the savvy hacker99Chapter 5. Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1015.1 Introduction to availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1025.2 What is availability?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1025.2.1 Outages - planned and unplanned . . . . . . . . . . . . . . . . . . . . . . . . . 1035.3 Inhibitors to availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1045.4 Redundancy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1055.4.1 Concurrent maintenance and upgrades . . . . . . . . . . . . . . . . . . . . . 1085.4.2 Accessing peripheral devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1095.4.3 Continuous availability of mainframes using clustering. . . . . . . . . . 1125.5 z/OS elements for availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1145.5.1 z/OS components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1155.5.2 Error recording . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1165.5.3 Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1175.6 Disaster recovery (DR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1185.7 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1215.8 Questions for review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1225.9 Instructor notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123Chapter 6. Accessing large amounts of data . . . . . . . . . . . . . . . . . . . . . . 1336.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1346.2 Channel subsystem. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1356.3 Control units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136Contentsv

6.4 DASD CKD architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1366.5 Mapping for access to devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1386.6 DASD subsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1396.7 Redundant Array of Independent Disks (RAID) . . . . . . . . . . . . . . . . . . . 1406.8 Reducing the number of logical volumes . . . . . . . . . . . . . . . . . . . . . . . . 1416.9 Multiple Allegiance/Parallel Access Volumes . . . . . . . . . . . . . . . . . . . . . 1426.10 Random access to data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1446.11 Databases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1446.12 Data sharing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1456.13 Data Facility Storage Management System . . . . . . . . . . . . . . . . . . . . . 1456.14 Data placement and management . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1466.15 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1486.16 Questions for review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1496.17 Topics for further discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1496.18 Instructor notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150Chapter 7. Systems management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1517.1 Introduction to systems management . . . . . . . . . . . . . . . . . . . . . . . . . . . 1527.2 System data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1537.3 Configuration management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1557.3.1 System software configuration management . . . . . . . . . . . . . . . . . 1567.3.2 Hardware configuration management . . . . . . . . . . . . . . . . . . . . . . . 1587.3.3 Application configuration management . . . . . . . . . . . . . . . . . . . . . . 1597.4 Workload management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1597.5 Operations management. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1607.5.1 Batch scheduling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1617.5.2 Console operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1617.6 Network management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1637.7 Storage management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1637.8 Security management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1637.9 Performance management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1647.9.1 z/OS implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1657.10 Problem management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1677.10.1 Trend reporting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1677.10.2 Operator console. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1677.11 Change management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1677.12 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1687.13 Instructor notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1697.13.1 Refer to 7.4 Performance management . . . . . . . . . . . . . . . . . . . . 169Chapter 8. Autonomic computing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1758.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1768.1.1 Autonomic computing principles . . . . . . . . . . . . . . . . . . . . . . . . . . . 176viIntroduction to the New Mainframe: Large-Scale Commercial Computing

8.28.38.48.58.68.78.88.1.2 Autonomic computing concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . 178z/OS implementation of autonomic computing . . . . . . . . . . . . . . . . . . . . 184Self-healing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184Self-configuring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186Self-protecting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187Self-optimizing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188Instructor notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1908.8.1 General reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190Appendix A. Architecture summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191Interrupt processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192The program status word . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192New and old PSWs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195Appendix B. Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197Notices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238Related publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239IBM Redbooks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239IBM white papers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240Other publications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240Online resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241How to get IBM Redbooks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242Help from IBM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243Contentsvii

viiiIntroduction to the New Mainframe: Large-Scale Commercial Computing

PrefaceToday, mainframe computers play a central role in the daily operations of most ofthe world’s largest corporations. While other forms of computing are used inbusiness in various capacities, the mainframe occupies a prominent place intoday’s e-business environment. In banking, finance, health care, insurance,utilities, government, and a multitude of other public and private enterprises, themainframe computer continues to provide the foundation of large-scalecomputing to modern business.The reasons for mainframe use are many, but generally fall into one or more ofthe following categories: CapacityScalabilityIntegrity and securityAvailabilityAccess to large amounts of dataSystem managementAutonomic capabilitiesThe mainframe owes much of its popularity and longevity to its inherent reliabilityand stability, a result of continuous technological advances since the introductionof the IBM System/360 in 1964. No other computer architecture in existencecan claim as much continuous, evolutionary improvement, while maintainingcompatibility with existing applications.This IBM Redbook is designed for readers who already possess a basicknowledge of mainframe computing, but need a clearer understanding of how theconcepts ranging from capacity through to autonomic capabilities relate tomainframe planning, implementation, and operation.For readers who need more introductory information about mainframe concepts,usage, and architecture, we recommend that you complete Introduction to theNew Mainframe: z/OS Basics, SG24-6366, prior to starting this book. And formore detailed information about z/OS programming topics, refer to the 11-volumeIBM Redbook series ABCs of z/OS System Programming. All of thesepublications are available at the following site:http://www.redbooks.ibm.com Copyright IBM Corp. 2006. All rights reserved.ix

How this text is organizedIn this document, we use simplified examples and focus mainly on basic systemfunctions. Hands-on exercises are provided to help you explore the mainframestyle of computingHow each chapter is organizedEach chapter follows a common format: Objectives for the reader Topics that teach a central theme related to mainframe computing Summary of the main ideas of the chapter A list of key terms introduced in the chapter Questions for review to help readers verify their understanding of the materialAbout the authorsMike Ebbers has worked for IBM for 33 years, specializing in mainframetechnology. He produces textbooks and IBM Redbooks about mainframes,which are available at the following site:http://www.ibm.com/mainframes/Frank Byrne is a Senior IT Specialist in the United Kingdom who providesday-to-day technical guidance and advice on the usage of z/OS and associatedproducts. He has 39 years of experience in large systems support. His areas ofexpertise include Parallel Sysplex implementation and DFSMS. Frank has writtenextensively about Parallel Sysplex usage.Pilar Gonzalez Adrados is an IT Specialist with IBM in Spain, and has morethan 25 years of experience in mainframe technology. She has been an ITEducation Specialist as well as a System Engineer. Pilar’s areas of expertiseinclude z/OS system management, mainframe hardware, and ParallelSysplex .Rodney Martin is a Senior Infrastructure Operator with IBM in Sydney, Australia.He joined IBM eight years ago, and has been operationally involved with MVS and z/OS systems for 18 years. Rodney has developed operating proceduresand training plans for both IBM Australia and other Australian commercialcompanies.Jon Veilleux is a Senior Systems Engineer at Aetna Inc. in Middletown, CT. Hehas 26 years of experience in z/OS installation, support, and problem resolution.Jon’s responsibilities include training junior systems programmers andxIntroduction to the New Mainframe: Large-Scale Commercial Computing

participating in the problem resolution swat team. Jon is Aetna's infrastructurerepresentative to the IBM zSeries Business Leaders Council.AcknowledgementsEdward Baker is a Senior Software Engineer with IBM Systems and TechnologyGroup Lab Services. He has more than 28 years of experience in z/OS softwaredevelopment. Ed’s areas of expertise include DFSMS, DFSMShsm , andDFSMSdss , as well as various IBM storage hardware and software products.Myriam Duhamel is an IT Specialist in Belgium. She has 20 years of experiencein application development and has worked at IBM for 15 years. Her areas ofexpertise include development in different areas of IBM System z . Myriamcurrently teaches courses in DB2 and WebSphere MQ.Andreas Gallus is an Advisory IT Architect for IBM Global Business Services inHamburg, Germany. He more than seven years of experience with mainframetechnology, along with Linux for zSeries and z/OS. His areas of expertiseinclude infrastructure architectures and server consolidation.Michael Grossmann is a Systems Engineer and IT Education Specialist inGermany. He has 12 years of experience as a z/OS Systems Programmer andInstructor. Michael’s areas of expertise include z/OS education for beginners,z/OS operations, automation, mainframe hardware and Parallel Sysplex.John Kettner is a Consulting Software Architect in the zSeries AdvancedArchitecture Group. He has 30 years of mainframe experience and holds a BS inComputer Science from L.I.U. His areas of expertise include zSeries internals,WebSphere product integration, and capacity planning. John has written severalIBM Redbooks and contributes to various education programs throughout IBM.Bianca Potthast is a Systems Programmer at LVM Versicherungen, Germany.She has 14 years of experience with z/OS and Storage Systems. Bianca’s areasof expertise include installation and configuration of hardware and storage.ReviewersOlegario Hernandez, ChileSeymour Metz, New York, USAJoe Macera, California, USAPrefacexi

xiiIntroduction to the New Mainframe: Large-Scale Commercial Computing

1Chapter 1.The new mainframeObjective:This chapter explains what the term mainframe means and describes howthey are used.After completing this chapter, you will be able to do the following: Explain why 60% of the world’s business data resides on mainframesList typical uses of mainframesDescribe the benefits of mainframe computingOutline the major types of workloads for which mainframes are best suited Copyright IBM Corp. 2006. All rights reserved.1

1.1 What is a mainframe?Today, the term mainframe can be used to describe a style of operation,applications, and operating system facilities. Here is a working definition: “Amainframe is what businesses use to host their commercial databases,transaction servers, and applications that require a greater degree of securityand availability than is commonly found on smaller-scale machines.”A mainframe is the central data repository or hub in a corporation’s dataprocessing center, linked to users through less powerful devices such asworkstations or terminals. The presence of a mainframe often implies acentralized form of computing, rather than a distributed form of computing.Having data centralized in a single mainframe repository saves users fromhaving to manage updates to more than one copy of their business data. Thisincreases the likelihood that the data is current and has integrity, because thereis only one version of data.Early mainframe systems were housedin enormous, room-filling metal boxes orframes, and this is probably how theterm “mainframe” originated. Themainframe required large amounts ofelectrical power and air-conditioning,and the room was occupied mostly byinput/output (I/O) devices. Also, atypical installation had severalmainframes installed with most of the I/O devices connected to all of themainframes. During their largest period in terms of physical size, a typicalmainframe occupied 2,000 to 10,000 square feet (600 to 3,000 square meters),with some installations being much larger than this.MainframeHosts thedatabases,transactionservers, andapplicationsthat require agreat degree ofsecurity andavailability.Starting around 1990, mainframe processors and most ofthe I/O devices became physically smaller, while theirfunctionality and capacity continued to grow. Mainframesystems today are much smaller than earlierones—about the size of a large refrigerator. Furthermore,it is now possible in some cases to run a mainframeoperating system on a personal computer that emulatesan IBM System z processor. Such emulators are usefulfor developing and testing business applications beforemoving them to a mainframe production system.Clearly, the term mainframe has expanded beyond merely describing thephysical characteristics of a system. Instead, the word typically applies to somecombination of the following attributes:2Introduction to the New Mainframe: Large-Scale Commercial Computing

Compatibility with mainframe operating systems, applications, and data. Centralized control of resources. Hardware and operating systems that can share access to disk drives withother systems, with automatic locking and protection against destructivesimultaneous use of disk data. A style of operation, often involving dedicated operations staff who use highlyorganized procedures for backup and recovery, training, and disasterrecovery at an alternate site. Hardware and operating systems that routinely work with hundreds orthousands of simultaneous I/O operations. Clustering technologies that allow the client to operate multiple copies of theoperating system as a single system.This configuration, known as Parallel Sysplex, is analogous in concept to aUNIX cluster, but allows for systems to be added or removed as neededwhile applications continue to run. This flexibility allows mainframe clients tointroduce new applications, or discontinue using existing applications, inre

New Mainframe: z/OS Basics, SG24-6366, prior to starting this book. And for more detailed information about z/OS programming topics, refer to the 11-volume IBM Redbook series ABCs of z/OS System Programming. All of these publications are available at the following site: