Stephen Linkin Houston Community College January 15, 2007 © 2002 - Mike Murach & Associates, 2007 - HCC, IBM 1 Introduction To IBM Mainframe Systems Chapter.

January 15, 2007

© 2002 - Mike Murach & Associates, 2007 - HCC, IBM 1

Stephen LinkinHouston Community College

Introduction To IBM Mainframe Systems

Chapter 1-2 ReviewChapter 1-2 Review

© 2002 - Mike Murach & Associates, 2007 - HCC, IBM

2

Objectives

Identify Basic Components Of Mainframe ProcessorsIdentify Basic Components Of Mainframe Processors Identify Difference In ArchitectureIdentify Difference In Architecture

IBM’s z/Series Processors And Earlier SystemsIBM’s z/Series Processors And Earlier Systems Types Of I/O Devices On MainframesTypes Of I/O Devices On Mainframes Define Tracks And CylinderDefine Tracks And Cylinder Describe Features Of Mainframe OS:Describe Features Of Mainframe OS:

Virtual StorageVirtual Storage MultiprogrammingMultiprogramming SpoolingSpooling Batch ProcessingBatch Processing Time Sharing.Time Sharing.

Describe MVS, OS/390, And Z/OsDescribe MVS, OS/390, And Z/Os


3

MainStorage

Channel 0

Channel 1

Channel 2

Channel 3

Channel 4

Channel 6

Channel 7

Channel 8

CPUI/O

devices

Processor

Figure 1-01a

The z/OS Redbook Shows How It Evolved Into---The z/OS Redbook Shows How It Evolved Into---

The Basic Architecture For IBM Mainframe Systems


4

Hardware Terms You Should Know

Central processing unit, or CPUCentral processing unit, or CPU CacheCache Channels (ESCON/FICON channels)Channels (ESCON/FICON channels) I/O devicesI/O devices Multiprocessor systemsMultiprocessor systems PR/SMPR/SM Logical partitions (LPAR’s)Logical partitions (LPAR’s)


5

Direct access storage devices, or DASDDirect access storage devices, or DASD Tape Drives and Optical DisksTape Drives and Optical Disks Display And Other TerminalsDisplay And Other Terminals PrintersPrinters

I/O Devices That Connect To Mainframe Servers


6

Program A

Program B

Program C

CPU

Mainframe system

Virtual storage

Real storage(main

storage)

Diskstorage

Figure 1-08a

Virtual Storage

An overview of virtual storage and multiprogramming


7

Printed output

Program A“pr inted” output

Program B“pr inted” output

Program C“pr inted” output

Fi le for programA output

Spooling disk

Outputto pr inter

Mainframe system

Fi le for programB output

Fi le for programC output

Figure 1-09a

Spooling

How the operating system spools output from application programs


8

Mainframe system

CPU

Jobscheduler

JOB 1JOB 3

JOB 2:Program AProgram BProgram C

JOB 1:Program AProgram B

JOB 2:Program AProgram BProgram C

JOB 3:Program A

Figure 1-10a

Batch Processing

Job Control LanguageJob Control Language

How batch processing works


9

Mainframe system

Runningorder entry

program

Runningorder entry

program

Creat ingJCL for

batch job

Developingappl icat ion

program

User 1 User 2 User 4User 3

Figure 1-11a

Time Sharing

Multiple users in a time sharing environment


10

Figure 1-12a

Time Line

The evolution of the OS/390 and z/OS operating system


11

A Partial Listing Of OS/390 And z/OS Services

Base Control Program (BCP or MVS)Base Control Program (BCP or MVS) Workload Manager (WLM)Workload Manager (WLM) Systems Management ServicesSystems Management Services Application Enablement ServicesApplication Enablement Services OS/390 UNIX System ServicesOS/390 UNIX System Services Distributed computing servicesDistributed computing services Communication ServerCommunication Server LAN Services Network Computing ServicesLAN Services Network Computing Services Network File System (NFS)Network File System (NFS) Softcopy ServicesSoftcopy Services


12

New Features In z/OS Version 1, Release 2

HiperSocketsHiperSockets TCP/IP Networking enhancementsTCP/IP Networking enhancements Internet and Intranet Security enhancementsInternet and Intranet Security enhancements Distributed PrintDistributed Print New File System and C++ compilerNew File System and C++ compiler Intelligent Resource Director (IRD)Intelligent Resource Director (IRD)


13

OS/390 and z/OS concepts and termsOS/390 and z/OS concepts and terms

Chapter 2


14

Objectives

Applied objectiveApplied objective Assign an appropriate name to a new data set.Assign an appropriate name to a new data set.

Knowledge objectivesKnowledge objectives Identify what an address space is.Identify what an address space is. In general terms, explain how address spaces are used to implement In general terms, explain how address spaces are used to implement

virtual storage and multiprogramming.virtual storage and multiprogramming. In general terms, explain how paging is used to transfer portions of an In general terms, explain how paging is used to transfer portions of an

address space to and from real storage.address space to and from real storage. In general terms, explain how swapping is used to transfer In general terms, explain how swapping is used to transfer

entire address spaces in and out of virtual storage.entire address spaces in and out of virtual storage. Identify the information contained in a volume label.Identify the information contained in a volume label. Describe the role of the VTOC in processing DASD Describe the role of the VTOC in processing DASD

data sets.data sets. Describe the three data set organizations that areDescribe the three data set organizations that are

most commonly used today: sequential, partitioned, most commonly used today: sequential, partitioned, and VSAM key-sequenced.and VSAM key-sequenced.

Distinguish between master and user catalogs.Distinguish between master and user catalogs. Describe how the high-level qualifier in a data set name Describe how the high-level qualifier in a data set name

is commonly used.is commonly used.


15

Objectives (2)

Knowledge objectives (Continued)Knowledge objectives (Continued) Describe unit allocation, volume allocation, and data set allocation.Describe unit allocation, volume allocation, and data set allocation. List and describe the three types of open modes that can be used to List and describe the three types of open modes that can be used to

open a file.open a file. Distinguish between a job and a job step.Distinguish between a job and a job step. Identify the basic functions of the JOB, EXEC, and DD JCL statements.Identify the basic functions of the JOB, EXEC, and DD JCL statements. Describe the basic function of a Job Entry Subsystem.Describe the basic function of a Job Entry Subsystem. Name the five steps that are involved in processing a job.Name the five steps that are involved in processing a job. Describe how the job class and priority affect the Describe how the job class and priority affect the

scheduling of a job.scheduling of a job. Describe the four types of SYSOUT data that are Describe the four types of SYSOUT data that are

produced by most jobs: the JES message log, the JCL produced by most jobs: the JES message log, the JCL listing, the system message log, and program output.listing, the system message log, and program output.

Describe how the output class affects the handling Describe how the output class affects the handling of SYSOUT data set.of SYSOUT data set.

Distinguish between system generation and Distinguish between system generation and system initialization.system initialization.


16

CPU

Mainstorage

Address space

Addressablestorage locations

Processor

Figure 2-01a

Address spaces

Key ConceptsKey Concepts


17

Uses DASD to Expand MemoryUses DASD to Expand Memory

Activepages

Addressspace 1

Addressspace 2

Addressspace 3

Addressspace 4

Expandedstorage(S/390

processors)

Page slots

Page frames

Realstorage

Pagedata set(DASD)

2GB

2GB 2GB 2GB 2GB

8GB

4Kpage

Figure 2-02a

Multiple Virtual Storage


18

Locating The PagesLocating The Pages

Swap datasets

Addressspace 1(swapped in)

Addressspace 5(swapped out)







Real storagePage datasets

CPU

Figure 2-03a

Address Space Swapping


19

Extended LSQA, SWA, andsubpool 229/230

Unallocated storage

LSQA, SWA, andsubpool 229/230

SQA, PLPA, and CSA

Unallocated storage

User region

System region

Nucleus

Extended nucleus

Extended user region

Extended SQA, PLPA,and CSA

Virtual storage

2GB

16MB

0MB

Privatearea

Extendedprivate area

Extendedcommon area

Common area

Figure 2-04a

A Virtual Storage Address Space

Two Basic AreasTwo Basic Areas The Private AreaThe Private Area The Common Area.The Common Area.

Special Provisions For The First Special Provisions For The First 16mb Of Address 16mb Of Address

Common Areas Have Two Common Areas Have Two Sections.Sections.

Above The 16MB LineAbove The 16MB Line Below It.Below It.

Common Area Contains Common Area Contains The NucleusThe Nucleus Other Operating System Data.Other Operating System Data.

The Private Area ContainsThe Private Area Contains Data Unique To Each User’s Data Unique To Each User’s

Address SpaceAddress Space The Program Being Executed.The Program Being Executed.


20

Expanded

storage

Realstorage

Dataspace

Hiperspace

4KB blocks

Address space

Figure 2-05a

Dataspaces And Hiperspaces On A System

DefinitionsDefinitions


21

Freeextents

VTOCFILE-BFILE-CFILE-BVTOC FILE-A

VOL1 label

FILE-A

FILE-B

FILE-C

Free extent

FILE-B

Free extent

Free extent

Diskvolume

Figure 2-06a

DASD Labels Identify Files On A Volume

z/OS identifies data sets on DASD with labels.z/OS identifies data sets on DASD with labels. DASD volumes contain a volume label,DASD volumes contain a volume label, The VTOC (Volume Table of Contents) contains labels calledThe VTOC (Volume Table of Contents) contains labels called

Data Set Control Blocks, or DSCBs, Data Set Control Blocks, or DSCBs,


22

LengthLength1 to 44 characters (standard)1 to 44 characters (standard)

1 to 35 characters (generation data group; see chapter 12) 1 to 35 characters (generation data group; see chapter 12) Only first 17 characters are used for tape data sets Only first 17 characters are used for tape data sets

CharactersCharacters Alphanumeric (A-Z, 0-9) Alphanumeric (A-Z, 0-9)

National (@,#, and $) National (@,#, and $) Period (.) Period (.)

QualifiersQualifiersData set names with more than 8 characters broken intoData set names with more than 8 characters broken into

qualifiersqualifiers 1 to 8 characters. Separate qualifiers with periods. 1 to 8 characters. Separate qualifiers with periods.

First character First character The first character of each qualifier must be a letter or The first character of each qualifier must be a letter or national character. national character.

Last characterLast characterThe last character of a data set name should not be a The last character of a data set name should not be a

period.period.

Rules For Forming Data Set Names

A valid data set nameA valid data set nameAR.TRANS.Y2001AR.TRANS.Y2001


23

A file with sequential organization by employeenumber

A file with VSAM key-sequenced organization,indexed by employee number

Figure 2-07a

SocialSecuritynumber

Employeenumber

Disklocation

12345

498-27-6117213-64-9290279-00-1210499-35-5079334-96-8721

First name

ThomasWilliamConstanceRonaldMarie

Middleinitial

TJM

L

Last name

BluestoneCollinsHarrisGarciaAbbott

0100301054017020214502181

Employeenumber

Disklocation

12345

SocialSecuritynumber

498-27-6117213-64-9290279-00-1210499-35-5079334-96-8721

First name

ThomasWilliamConstanceRonaldMarie

Middleinitial

TJM

L

Last name

BluestoneCollinsHarrisGarciaAbbott

Data component

Disklocation

Employeenumber

Index component

0100301054017020214502181

12345

0100301054017020214502181

File Organization


24

PAY1000 PAY2000 PAYTRAN . . .

Directory

IDENTIFICATION DIVISION.* PROGRAM-ID. PAY1000.* ENVIRONMENT DIVISION.* INPUT-OUTPUT SECTION.* FILE-CONTROL.* SELECT PAYMAST ASSIGN TO PAYMAST. . . .

Member PAY1000

Data set name: MM01.TEST.COBOL

IDENTIFICATION DIVISION.* PROGRAM-ID. PAY2000.* ENVIRONMENT DIVISION.* INPUT-OUTPUT SECTION.* FILE-CONTROL.* SELECT PAYTRAN ASSIGN TO PAYTRAN. . . .

Member PAY2000

01 PAYROLL-TRANSACTION-RECORD.* 05 PT-EMPLOYEE-NUMBER PIC 9(6). 05 PT-TRAN-DATE PIC 9(6). 05 PT-TRAN-SERIAL PIC 9(7). 05 PT-TRAN-TYPE PIC X. 05 PT-TRAN-AUTHORIZATION PIC 99.

Member PAYTRAN

Figure 2-08a

Partitioned Data Set With Three Members


25

The relationships among the master catalog, user The relationships among the master catalog, user catalogs, and data setscatalogs, and data sets

Mastercatalog

Usercatalogs

VSAMdata sets

VSAMdata sets

Non-VSAMdata sets

Non-VSAMdata setsFigure 2-09a

Catalog Structure


26

Character Hex Character Hex Character Hex Character Hex Character Hex

space 40 0 F0 . 4B A C1 J D1 1 F1 ( 4D B C2 K D2 S E2 2 F2 + 4E C C3 L D3 T E3 3 F3 & 50 D C4 M D4 U E4 4 F4 $ 5B E C5 N D5 V E5 5 F5 * 5C F C6 O D6 W E6 6 F6 ) 5D G C7 P D7 X E7 7 F7 ; 5E H C8 Q D8 Y E8 8 F8 - 60 I C9 R D9 Z E9 9 F9

Figure 2-10b

The EBCDIC Codes For Alphanumeric Characters


27

The Three Levels Of Data Set Allocation

Level 1: Unit allocationLevel 1: Unit allocation generic namegeneric name or or group namegroup name.. A generic name an IBM-supplied name indicating a device typeA generic name an IBM-supplied name indicating a device type A group name, or esoteric name, flexible way to allocate units.A group name, or esoteric name, flexible way to allocate units.

Level 2: Volume allocationLevel 2: Volume allocation Volume serial number (vol-ser).Volume serial number (vol-ser). Non-specific volume request Non-specific volume request

Non-specific volume requests aren’t valid for existing data sets.Non-specific volume requests aren’t valid for existing data sets.

Level 3: Data set allocationLevel 3: Data set allocation For new data sets, file labels are created, space allocated, and For new data sets, file labels are created, space allocated, and

the VTOC is updated.the VTOC is updated.


28

OS/390

Program

QSAM

VSAM

Data

Input

Output

I/O

Data set open modes

Access methodsI/O requests

Read

Write

Read/Rewrite

Figure 2-12a

How Data Sets Are Processed


29

What This Course Is About

JobsJobs Job Control Language JCLJob Control Language JCL JESJES


30

JCL statements for a job that prints a report//MM01RN JOB (36512),'R MENENDEZ',NOTIFY=MM01//RPTRUN EXEC PGM=RPT3000//CUSTMAST DD DSNAME=MM01.CUSTOMER.MASTER,DISP=SHR//SALESRPT DD SYSOUT=A//ERRLIST DD SYSOUT=A

JOBJOB information that identifies the job.information that identifies the job. EXECEXEC Indicates the program to be executed.Indicates the program to be executed. DDDD Identifies a file to be processed. Identifies a file to be processed.

Three Basic JCL Statements


31

How JES2 and JES3 process jobs

How a job enters the systemHow a job enters the system Entering JCL commands into a display terminal.Entering JCL commands into a display terminal. Terminal user issues:Terminal user issues:

SUBMIT, or SUB, commandSUBMIT, or SUB, command JES2 or JES3 then copies it to the queue on the JES spool.JES2 or JES3 then copies it to the queue on the JES spool.

Scheduling for executionScheduling for execution JES examines jobs in the queue and prioritizes the work.JES examines jobs in the queue and prioritizes the work. Job class and priority classify a job’s importance.Job class and priority classify a job’s importance.

An initiator program runs in the system region of an address An initiator program runs in the system region of an address space eligible for batch job processing.space eligible for batch job processing.

Each initiator can handle one job at a time.Each initiator can handle one job at a time.

The job issubmitted

The job isselected forexecution

The job isexecuted

The job’soutput is

processed

The job ispurged

Figure 2-13b


32

Job Classes

Typical job class assignmentsTypical job class assignments Job classJob class CharacteristicsCharacteristics AA Execute within 15 minutes of submission.Execute within 15 minutes of submission. BB Execute within 30 minutes of submission.Execute within 30 minutes of submission. CC Execute within 1 hour of submission.Execute within 1 hour of submission. DD Execute overnight.Execute overnight. HH Hold until released by an operator.Hold until released by an operator. LL Execute within 15 minutes of submission Execute within 15 minutes of submission

Each step is limited to 1 minute of execution time.Each step is limited to 1 minute of execution time. How job classes are assigned to initiatorsHow job classes are assigned to initiators

InitiatorInitiator Eligible job classesEligible job classes 11 AA 22 B,C,D,H,LB,C,D,H,L 33 B,CB,C 44 CC


33

Local system areas

Control blocks

System region

Private area

Initiator

Local system areas

Control blocks

System region

Private area

Initiator

Local system areas

System region

Private area

Initiator

User program

Control blocks

Local system areas

Control blocks

System region

Private area

Unallocation

Initiator

After the initiatorselects a job forexecution, it invokesthe interpreter, whichbuilds the requiredcontrol blocks in theaddress space’sSWA.

For each job step, theinitiator invokesallocation routines toallocate the units,volumes, and datasets required by thejob step.

After the job step’sresources have beenallocated, the initiatorcreates a user region,loads the userprogram into it, andtransfers control to theuser program.

When the userprogram completes,the initiator invokesunallocation routinesto deallocate theresources used by thejob step. Then, if thejob has more steps,the initiator repeatsthe allocation-execution-unallocationprocess.

AllocationInterpreter

Figure 2-15

How A Job Is Executed Once An Initiator Selects It


34

OUTPUT Controls

The SYSOUT data sets produced by most jobsThe SYSOUT data sets produced by most jobs SYSOUT data setSYSOUT data set DescriptionDescription JESMSGLGJESMSGLG A listing of messages produced by JES2 or JES3A listing of messages produced by JES2 or JES3

as the job was executed. as the job was executed. JESJCL JESJCL The JES JCL listing is a listing of the JCLThe JES JCL listing is a listing of the JCL

processed by the job. processed by the job. JESYSMSGJESYSMSG The system message log is a collection of The system message log is a collection of

message produced as the job was executed. message produced as the job was executed. SYSOUT SYSOUT SYSOUT data produced by a program executedSYSOUT data produced by a program executed

in the job. in the job. Typical output class assignmentsTypical output class assignments

Output classOutput class Type of outputType of output AA Standard printer output, routed to one of the Standard printer output, routed to one of the

installation’s high-speed printers installation’s high-speed printers BB Special printer output.Special printer output. XX Held output that stays on the SYSOUT queue Held output that stays on the SYSOUT queue

until released for printing or deleted. until released for printing or deleted.


35

SYSGEN

System generationSystem generation System generationSystem generation (sysgen) creates the system. (sysgen) creates the system. IBM sends or Downloads distribution libraries. IBM sends or Downloads distribution libraries.

System generation selects and assembles System generation selects and assembles components needed to create a working system.components needed to create a working system.

Systems programmer codes special macro Systems programmer codes special macro instructions specifying how components instructions specifying how components should be put together.should be put together.

The output is a series of system libraries The output is a series of system libraries containing, the executable code that makes up containing, the executable code that makes up the operating system.the operating system.


36

Initialization

System initializationSystem initialization The process of starting a previously generated The process of starting a previously generated

systemsystem Immediately after sysgenImmediately after sysgen Reinitialized due to system maintenance or a system Reinitialized due to system maintenance or a system

error.error.

Operator uses the system console to start Operator uses the system console to start an an Initial Program LoadInitial Program Load, or , or IPLIPL.. System clears its real storageSystem clears its real storage Loads the operating system from the system Loads the operating system from the system

libraries libraries


37

End Presentation

Stephen Linkin Houston Community College January 15, 2007 © 2002 - Mike Murach & Associates, 2007 - HCC, IBM 1 Introduction To IBM Mainframe Systems Chapter.

Documents

mike murach associates

multiprogramming slide

environment slide

review slide

mainframe servers slide

v virtual storage

overview of virtual

real storage