Basics of Mainframes

Level II Knowledge of Dataset Structure

Physical Sequential (PS)

It contains records that are stored in physical order.It’s just like a file in other file system. New records can be appended to the existing data.

Partitioned Data set (PDS)

It contains a group of sequentially organized member.Each member indicates an individual data set, contains data.

Partitioned Data set Extended (PDSE)

It is similar to that of a PDSThe main advantage of a PDSE is that it automatically reuses space within the data set.

Virtual Storage Access Method (VSAM)

VSAM is an access method service used to organize data and maintain information about the data in a catalog.It arranges records by an index key, relative record or relative byte address.It is used for direct or sequential processing of fixed-length and variable length records on DASD.The two major parts of VSAM are,

Catalog Management – it contains information about the dataset Record Management - it can be used to organize records into four

types of data sets, they are, KSDS – Key sequenced Data set ESDS – Entry sequenced Data set LDS – Linear Data set RRDS – Relative Record Data set

KSDS

A KSDS VSAM data set contains records in order by a key field and can be accessed by the key or by a relative byte address. The key contains a unique value, such as an employee number or part number.

ESDSAn ESDS VSAM data set contains records in the order in which they

were entered and can only be accessed by relative byte address. An ESDS is similar to a sequential data set.

LDSAn LDS VSAM data set contains data that can be accessed as byte-

addressable strings in virtual storage. A linear data set does not have imbedded control information that other VSAM data sets hold.


RRDSAn RRDS VSAM data set contains records in order by relative-record

number and can only be accessed by this number. Relative records can be fixed-length or variable-length.

VSAM Data set components

A component is an individual part of a VSAM data set.Each component has a name, and an entry in catalog and VTOC.The two components includes,

Data componentIndex component

Data componentAll VSAM data set has a data component.It is a part of VSAM data set which contains the data records.

Index componentIt is a collection of records containing data keys and pointers (relative

byte address). With the help of index, a vsam is able to retrieve logical records from a data component.

VSAM Physical Record and Logical Record

Physical Record:A Physical record is device independentWhen a data set is defined, VSAM calculates the physical record size.All physical record contains the same length.Physical record can also be called as physical block.It can also contain control information along with logical record in a physical

record.

Logical Record:It is a unit of information used to store data in VSAM data set.It is designed by, an application programmer.A logical record can be of a fixed size or variable size.

VSAM Control Interval CIA control interval is usually formed by one or more physical record.CI is a contiguous area of direct access storage that VSAM uses to store data records and control information that describes the records.It is a unit of information that VSAM transfers between storage device and the processor during one I/O operation.Whenever a record is retrieved from direct access storage, the entire CI containing the record is read into a VSAM I/O buffer in virtual storage.

VSAM Control Area CAA CA is formed by two or more CI’s put together into fixed-length contiguous areas of direct access storage.A VSAM data set can be composed of one or more control areas.The minimum size of a CA is one track.The CA size is implicitly defined when you specify the size of a data set at

data set definition.


Generation Data Group

Generation of related data set or successive updates can be cataloged in to a single GDG.Each data set in a gdg is referred to a generation data set (GDS).Generation data sets can be sequential, PDS, direct, or indexed sequential.Each GDG is represented by a GDG base entry.The GDG base is a construct that exists only in a user catalog; it does not exist as a data set on any volume.The GDG base is used to maintain the generation data sets.The main advantage of using GDG is,

All of the data sets in the group can be referred to by a common name The operating system is able to keep the generations in chronological order

(arranged in some ordering means). Outdated or obsolete generations can be automatically deleted by the

operating system.

Indexed Sequential Access Method (ISAM)

ISAM refers to two access methods: Basic indexed sequential access method (BISAM) Queued indexed sequential access method (QISAM).

Data sets that ISAM processes are called indexed sequential data sets. ISAM arranges records in sequence by key fields, and retrieves records by key. The structure of multilevel indexes in ISAM is similar to the structure of indexes in VSAM.

Object Access Method (OAM)

OAM processes very large named byte streams (objects) that have no record boundary orother internal orientation. These objects can be recorded in a DB2 data base or on an optical storage volume.

Level II Types of DASD and tapes

Types of DASD

Traditional DASD 3380 Models J, E, K 3390 Models 1, 2, 3, 9 DASD based on RAID technology RAMAC Array RAMAC Virtual Array (RVA) Enterprise Storage Server (ESS)

DASD capacity

Physicalcharacteristics

3380-J 3380-E 3380-K

3390-1 3390-2 3390-3 3390-9

Data Cyl/Device

855 1770 2655 113 2226 3339 10017

Track/Cyl 15 15 15 15 15 15 15

Bytes/Trk 47476 47476 47476 56664 56664 56664 56664

Bytes/Cylinder

712140

712140

712140

849960

849960

849960

849960

MB/Device 630 1260 1890 946 1892 2838 8514

Large volume support

A "large volume" is larger than a 3390-9 The largest possible volume has 32760 (3390) cylinders That would be a "3390-27" if it had its own device type Almost 28 GB

Level II Types of DASD and tapes

TAPE CAPACITYThe capacity of a tape depends on the device type that is recording it. 3480

and 3490 tapes are physically the same cartridges. The IBM 3590 and 3592 high performance cartridge tape is not compatible with the 3480, 3490, or 3490E drives. 3490 units can read 3480 cartridges, but cannot record as a 3480, and 3480 units cannot read or write as a 3490.

Product Capacity (Mb) Transfer Rate (KB/S)

IBM 3480 200 3,000

IBM 3490 200 4,500

IBM 3490E 400 9,000

IBM 3490E 800 9,000

IBM 3590 Magstar 10,000 (uncompacted) 9,000 (uncompacted)

IBM 3590E Magstar 20,000 (uncompacted) 14,000

IBM 3590E Magstar XLCartridge

20,000/40,000 (dependent onModel B or E)

14,000

IBM 3592 TotalStorageEnterprise Tape Drive

300,000 (for high capacityrequirements)or60,000 (for fast data accessrequirements)

40,000

Level II Basic JCL Coding Skills

JCL is a Job Control LanguageIt is a means of communication between a program (COBOL, Assembler) and the MVS operating system.With out JCL your program will not run on IBM mainframe.

Components of JCL Statements:The components includes,

//Name FieldOperation FieldOperand

Description // NAME Operation OperandJob Identification

// JOB1 JOB Parameter

Program Identification

// STEP01 EXEC PGM=’ ‘

INPUT/OUTPUT File Identification

// INPUT01 DD DSN=’ ‘DISP=(--,--,--)

// PRINT01 DD SYSOUT=A

The above described table contains the general structure for a JCL.

JOB STATEMENT

All JCL must contain a JOB statement. A general Job statement for a JCL look like this,

// JOB Job Name Positional Parameter Keyword Parameter

Positional ParameterPositional Parameter includes

Job Accounting Information Parameter Programmer Name Parameter

Job Accounting Information ParameterIt identifies the account number which will be billed for the CPU time utilized

on the mainframe.e.g. //JOB1 JOB (A123, DEPT1)

Programmer Name ParameterIt identifies the name of a person or the information related to the job being

submitted.e.g. //JOB1 JOB (A123, DEPT1), ‘xxxxxxxx’

Keyword ParameterThe keyword parameter must follow the positional parameter.Keyword Parameter includes,

CLASS

PRTY MSGCLASS MSGLEVEL TYPRUN


CLASS ParameterIt identifies the nature of the job that is to be submitted. The job class is used to identify the characteristics (long-running job, short running job, utilizes heavy resources) to the operating system.Syntax: CLASS=job classWhere, job class is any character between A-z and 0-9.e.g. //JOB1 JOB (A123, DEPT1), ‘xxxxxxxx’, CLASS = A

PRTY ParameterA job with higher number will take precedence over a job with lower priority.If both jobs contain same job class and priority then it will be executed in the order the job has been submitted.Syntax: PRTY=9e.g. //JOB1 JOB (A123, DEPT1), ‘xxxxxxxx’, CLASS = A, PRTY= 6

MSGCLASS ParameterIt determines the output device to which system messages and JCL messages are written.Syntax: MSGCLASS = output class name.Where, output class-name is any character between A-z and 0-9.e.g. //JOB1 JOB (A123, DEPT1), ‘xxxxxxxx’, CLASS = A, PRTY= 6, MSGCLASS = A

MSGLEVEL ParameterIt specifies the JCL and allocation messages that will be recorded on the

output deviceAs a JCL is submitted, all kinds of messages are generated by the system.

Log message indicating job name, user name etc. are routed to output device.

JCL statement comprising that job is output.Messages related to the execution of the job will be outputThe output of the program being executed is output

Syntax: MSGLEVEL = (statement, messages)Where statements can be 0, 1 or 2 and messages can be 0 or 1Statement 0 Indicates the messages related to the job statement.Statement 1 Indicates all JCL in the job being submitted.Statement 2 Indicates only the input JCL statements being printed.Message 0 indicates only allocation/termination message if the job

terminates abnormally.Message 1 Indicates only allocation/termination message if the job

terminates abnormally.e.g. //JOB1 JOB (A123, DEPT1), ‘xxxxxxxx’, CLASS = A, PRTY= 6, MSGCLASS =

A, MSGLELEL (0, 0)

TYPRUN ParameterIt is used to specify the type of job processing such as,

Whether a job is to be held until it is releasedWhether its execution is to be suppressed altogetherSyntax: TYPRUN = HOLD or SCANHOLD – Results in the job bring held until further notice.

It is helpful when a job utilizes a lot of resourcesSCAN – The JCL is being scanned for syntax errors and reports them to the

output mediae.g. //JOB1 JOB (A123, DEPT1), ‘xxxxxxxx’, CLASS = A, PRTY= 6, MSGCLASS =

A,MSGLELEL (0, 0), TYPRUN=SCAN


EXEC STATEMENTThe EXEC statement is the first statement of each job step.

Job stepA job step is a unit of work that is submitted to the operating system in the

form of a collection of JCL statements.A job can have many EXEC statements

Syntax: // Step-name EXEC PGM = program-name, Keyword Parameter

Step-name It is the name assigned to the job stepIt is optional field, since system messages reference step-names it is recommended to mention a unique meaningful name for each step.Syntax: // STEP01 EXEC PGM= program-nameStep name is mandatory when a reference is made to a step that has been previously executed.

EXEC It is the execute statement

Program name It is the name of the program that is to be executed, It is a positional parameterSyntax: // STEP01 EXEC PGM= program-name

Keyword parameter The keyword parameter includes,ACCTPARMADDRSPCDPRTYPERFORMRD

ACCT ParameterIt is used to supply accounting information for the job stepe.g. // Step-name EXEC PGM = PROGRAM2, ACCT = (123, SS)

PARM ParameterIt is used to supply information to a program as it executes.Syntax: PARM = value (value ranges from 0-100)e.g. // Step-name EXEC PGM = PROGRAM2, ACCT = (123, SS),

PARM=PRINT

ADDRSPC ParameterIt is used to indicate to the system that the job step is to use either virtual or real storage.Syntax: ADDRSPC = VIRT or REALe.g. // Step-name EXEC PGM = PROGRAM2, ACCT = (123, SS),

PARM=PRINT,ADDRSPC = REAL

DPRTY ParameterIt is used to assign a dispatching priority to the job step.It is used by the system to determine the order in which tasks are to be

executed.Syntax: DPRTY = (value1, value2)Value1 and Value2 range 0-15


DPRTY can be computed as,DPRTY = (value1)*16 + value2e.g. // Step-name EXEC PGM = PROGRAM2, ACCT = (123, SS),

PARM=PRINT,ADDRSPC = REAL, DPRTY= (10, 2)

In the above e.g. DPRTY = 162

PERFORM ParameterIt is used to specify the performance group for the job step.It determines the rate at which the job steps in a program have access to system resources.Syntax: PERFORM = n where n is the number from 1 to 999e.g. // Step-name EXEC PGM = PROGRAM2, ACCT = (123, SS),

PARM=PRINT,ADDRSPC = REAL, DPRTY= (10, 2), PERFORM = 10

RD (Restart Definition) ParameterIt is used to specify automatic restart of a job if it abends.Syntax: RD=R Restart

RD=NR No automatic restartRD=NC No checkpointRD=RNC Restart with No checkpoint

CheckpointIt is taken by the system to record the status of a program as it executes. The advantage of checkpoint is that, if a job abends, it can be restarted from the last successful checkpoint, rather than beginning from the first.e.g. // Step-name EXEC PGM = PROGRAM2, ACCT = (123, SS), PARM=PRINT,

ADDRSPC = REAL, DPRTY= (10, 2), RD=R

Parameter Applies to both JOB and EXEC StatementThe parameters that can be coded both in JOB and EXEC statement are

COND REGION TIME

COND Parameter

Each step within a job sends a return code to the system upon completion. This is called condition code.Condition code 00 implies successful completion of a job step.Condition code other than 00 implies unsuccessful execution of a job stepSyntax: COND=(comparison-code, condition)Where comparison code is a numeric value (0-4095)Condition is GT, GE, LT, LE, EQ, NE

GT Greater ThanGE Greater Than or equal toLT Less thanLE Less than or equal toEQ Equal toNE Not equal to

Condition Parameter specified in JOB statement implies to the entire job step.e.g. //JOB1 JOB (A123, DEPT1), ‘xxxxxxxx’, CLASS = A, PRTY= 6, MSGCLASS = A,

COND=(4,LT)Level II Basic JCL Coding Skills

//STEP1 EXEC PGM=Program1 // STEP2 EXEC PGM=Program2 // STEP3 EXEC PGM=Program3

In the above e.g. Assume that step1 executes successfully. The return code is 0. Then it will check for the condition code (Is the number 4 less than 0 – NO), then step2 will be executed. Incase step 2 returns 4 then once again it checks for the condition code (now 4 is equal to 4) so next step will be executed.

Condition Parameter specified in EXEC statement implies only to particular job stepe.g. //JOB1 JOB (A123, DEPT1), ‘xxxxxxxx’, CLASS = A, PRTY= 6, MSGCLASS = A, // STEP1 EXEC PGM=Program1 // STEP2 EXEC PGM=Program2, // COND = (8, EQ, STEP1)

In this e.g. The COND parameter specifies that STEP2 should be bypassed if 8 is equal to the return code issued by STEP1.

REGION ParameterAt the time that a job is run, a default amount of work space is assigned to it.In order to override this REGION parameter is used.Syntax: REGION = value1K (multiples of 1024 bytes)

REGION = value2M (multiples of one million bytes)IF REGION = 0k or 0M then all available storage is assigned to job or job step.

Region Parameter for Job statemente.g. //JOB1 JOB (A123, DEPT1), ‘xxxxxxxx’, REGION=96k // STEP1 EXEC PGM=Program1

Region Parameter for EXEC statemente.g. //JOB1 JOB (A123, DEPT1), ‘xxxxxxxx’ // STEP1 EXEC PGM=Program1, REGION=96k

TIME ParameterIt is used to specify the amount of CPU time that a job or job step is permitted to utilize before it is terminated.Syntax: Time = (minutes, seconds)

Minutes is the number from 1 to 1439Seconds is from 1 to 59

DD (Data Definition) StatementThe DD statement is used to identify the source of input and the placement of

output informationSyntax: // DDName DD Keyword Parameter


Keyword ParameterIt includes,

DSNDISPUNITSPACEDCBVOLUME

DSN (Data set Name) ParameterSyntax: DSN = dsn-name

DISP (Dispositional) ParameterSyntax: DISP = (status, normal-disposition, abnormal-disposition)Status field indicates the current status of the data setNormal-Disposition specifies how the data set is to be disposed upon normal execution of the job.Abnormal-Disposition specifies how the data set is to be disposed upon abnormal termination of the job.

Status Normal-disposition

Abnormal-disposition

New Delete DeleteOld Keep KeepMod Catlg UncatlgShr Uncatlg Catlg

pass

New – indicates that a new dataset is to be createdOld – indicates that a dataset already existsMod – used to modify sequential data setsShr – allows multiple jobs to read the same data set

e.g. //JOB1 JOB (A123, DEPT1), ‘xxxxxxxx’ // STEP1 EXEC PGM=Program1, REGION=96k

// DD DSN=USER1.SAMPLE.TEST // DISP=(NEW,CATLG,DELETE)

UNIT ParameterIt is coded on the DD statement to specify an input or output device that is to

be accessed.Syntax: UNIT = device address (e.g. s26)

UNIT = device type (e.g. 3390)UNIT = device group name (e.g. sysda)

e.g. //JOB1 JOB (A123, DEPT1), ‘xxxxxxxx’ // STEP1 EXEC PGM=Program1, REGION=96k // DD DSN=USER1.SAMPLE.TEST // DISP=(NEW,CATLG,DELETE) // UNIT=3390


VOL ParameterIt is coded on the DD statement to identify specific disk or tape volumes.Syntax: VOL=SER= serial-number (e.g. VOL=SER=ee469)

VOL=REF=*.referback (e.g. VOL = REF= *.STEP1.DD1) Refers to the previous DD statement for the volser

VOL=PRIVATE (exclusive use of volume for the data set specified in the job step)

VOL=RETAIN (the volume remains mounted until the completion of the job)

e.g. //JOB1 JOB (A123, DEPT1), ‘xxxxxxxx’ // STEP1 EXEC PGM=Program1, REGION=96k // DD DSN=USER1.SAMPLE.TEST // DISP=(NEW,CATLG,DELETE) // UNIT=3390, VOL=SER=EE469

SPACE ParameterIt is coded on the DD statement used to allocate storage for new data set on

DASD.Space can be in tracks, cylinders, blocks.Syntax: SPACE = (CYL, (primary, secondary, directory), RLSE, CONTIG, MXIG,

ROUND)SPACE = (TRK, (primary, secondary, directory), RLSE, CONTIG, MXIG,

ROUND)SPACE = (BLK, (primary, secondary, directory), RLSE, CONTIG, MXIG,

ROUND)

RLSE - Releases the allocated space when a data set is closed

CONTIG - Specifies only contiguous space should be allocated to the ds.

- Applies only to primary space allocation- Decreases data set access time- Drawback the job will be terminated if the contiguous

space is not found.

MXIG - It is used to specify that space requested should be allocated to

the largest contiguous area of space available on the volume.

- Applies only to primary space allocation

ROUND - The system computes the amount of storage required, rounds it

off to the nearest cylinder, and allocates that number of cylinders to the request.

e.g. //JOB1 JOB (A123, DEPT1), ‘xxxxxxxx’ // STEP1 EXEC PGM=Program1, REGION=96k // DD DSN=USER1.SAMPLE.TEST // DISP=(NEW,CATLG,DELETE) // UNIT=3390, VOL=SER=EE469 // SPACE = (CYL, (10, 5), RLSE)

DCB (Data Control Block) ParameterIt is used to supply information to the system that allows it to manage the data sets that are created as jobs are submitted.Syntax: DCB = (RECFM=format, LRECL=record-length, BLKSIZE=block-size)

RECFM – used to specify to the operating system the record format of

the data set being created.RECFM = F or FB or V or VB or U


Where, f-fixed, fb-fixed-block, v-variable, vb-variable-block ,u-undefined length

LRECL – specify the length of the record, in bytes.LRECL = number

BLKSIZE – specifies the block size of a data set in bytes.BLKSIZE = number

e.g. //JOB1 JOB (A123, DEPT1), ‘xxxxxxxx’ // STEP1 EXEC PGM=Program1, REGION=96k //DD1 DD DSN=USER1.SAMPLE.TEST, // DISP=(NEW,CATLG,DELETE), // UNIT=3390, VOL=SER=EE469, // SPACE = (CYL, (10, 5), RLSE), // DCB = (RECFM=F, LRECL=80, BLKSIZE = 800) //SYSPRINT DD SYSOUT=* //

Creating a GDG

//JOB1 JOB (A123, DEPT1), ‘xxxxxxxx’//STEP1 EXEC PGM=IDCAMS//GDGMOD DD DSNAME=USER1.GDG01.TEST, DISP=(,KEEP),// SPACE= (TRK,(0)),UNIT=DISK,VOL=SER=VSER03,

// DCB= (RECFM=FB, BLKSIZE=2000, LRECL=100)//SYSPRINT DD SYSOUT=A//SYSIN DD *DEFINE GENERATIONDATAGROUP -(NAME (GDG01) -EMPTY -NOSCRATCH -LIMIT (25))/*

EMPTY - It specifies that all existing generations of the GDG are to be uncataloged.

NOEMPTY - It specifies that only the oldest generation of the GDG is to be uncataloged if the limit is reached.

SCRATCH - It specifies that if the entry of a data set in a GDG is removed from the

index, then its entry should be physically deleted from the volume that it

resides on.NOSCRATCH - Indicates that the entry of the data set should only be uncataloged, not

physically deleted from the volume.LIMIT - It specifies the total number of generations that the GDG may contain.


Adding a new version to GDG

//JOB1 JOB (A123, DEPT1), ‘xxxxxxxx’//STEP1 EXEC PGM=IDCAMS//GDGMOD DD DSNAME=USER1.GDG01.TEST (+1),// DISP = (NEW, CATLG, DELETE) /*MANDATORY*///SYSPRINT DD SYSOUT=A/*

Modifying features of a GDGThis can be achieved through ALTER command.

//JOB1 JOB (A123, DEPT1), ‘xxxxxxxx’//STEP1 EXEC PGM=IDCAMS//SYSPRINT DD SYSOUT=A//SYSIN DD *

ALTER USER1.GDG01.TEST LIMIT (10)/*

Deleting a GDG

//JOB1 JOB (A123, DEPT1), ‘xxxxxxxx’//STEP1 EXEC PGM=IDCAMS//SYSIN DD

DELETE (USER1.GDG01.TEST) GDG/*

Deleting a GDG Version

//JOB1 JOB (A123, DEPT1), ‘xxxxxxxx’//STEP1 EXEC PGM=IDCAMS//DEL1 DD DSN = USER1.GDG01.TEST (+1),

DISP = (OLD, DELETE, DELETE)/*

Level II IBM Utilities

IEBCOMPR: Compare records in sequential or partitioned data sets, or PDSEs. Two sequential data sets are considered equal (that is, are considered to be identical) if:

The data sets contain the same number of records Corresponding records and keys are identical

Two partitioned data sets or two PDSEs are considered equal if:

Corresponding members contain the same number of records Note lists are in the same position within corresponding members Corresponding records and keys are identical Corresponding directory user data fields are identical

If all these conditions are not met for a specific type of data set, those data sets are

considered unequal. If records are unequal, the record and block numbers, the names of the DD statements that define the data sets, and the unequal records are listed in a message data set. Ten successive unequal comparisons stop the job step, unless you provide a routine for handling error conditions. You can run this sample JCL to compare two cataloged, partitioned organized (PO) data sets: IEBCOMPR SAMPLE

//DISKDISK JOB ...// EXEC PGM=IEBCOMPR//SYSPRINT DD SYSOUT=A//SYSUT1 DD DSN=PDSE1,DISP=SHR//SYSUT2 DD DSN=PDSE2,DISP=SHR//SYSIN DD * COMPARE TYPORG=PO/*

IEBCOPY: Copy, compress, or merge partitioned data sets or PDSEs; add RLD count information to load modules; select or exclude specified members in a copy operation; rename or replace selected members of partitioned data sets or PDSEs.

Make a copy of a PDS or PDSE Merge partitioned data sets (except when unloading) Create a sequential form of a PDS or PDSE for a backup or transport Reload one or more members from a PDSU into a PDS or PDSE Select specific members of a PDS or PDSE to be copied, loaded, or

unloaded Replace members of a PDS or PDSE Rename selected members of a PDS or PDSE

IEBCOPY utility example

//COPY JOB ...//JOBSTEP EXEC PGM=IEBCOPY//SYSPRINT DD SYSOUT=A//OUT1 DD DSNAME=DATASET1,UNIT=disk,VOL=SER=111112,// DISP=(OLD,KEEP)//IN6 DD DSNAME=DATASET6,UNIT=disk,VOL=SER=111115,// DISP=OLD


//IN5 DD DSNAME=DATASET5,UNIT=disk,VOL=SER=111116,// DISP=(OLD,KEEP)//SYSUT3 DD UNIT=SYSDA,SPACE=(TRK,(1))//SYSUT4 DD UNIT=SYSDA,SPACE=(TRK,(1))//SYSIN DD *COPY OUTDD=OUT1

INDD=IN5,IN6SELECT MEMBER=((B,,R),A)/*

IEBCOPY with copy and compress

//COPY JOB ...//JOBSTEP EXEC PGM=IEBCOPY//SYSPRINT DD SYSOUT=A//INOUT1 DDDSNAME=DATA.SET1,UNIT=disk,VOL=SER=111112,DISP=(OLD,KEEP)//IN5 DD DSNAME=DATA.SET5,UNIT=disk,VOL=SER=111114,DISP=OLD

//IN6 DD DSNAME=DATA.SET6,UNIT=disk,VOL=SER=111115,// DISP=(OLD,KEEP)//SYSUT3 DD UNIT=SYSDA,SPACE=(TRK,(1))//SYSUT4 DD UNIT=SYSDA,SPACE=(TRK,(1))

//SYSIN DD *COPY OUTDD=INOUT1,INDD=(IN5,(IN6,R),INOUT1)/*

IEBEDIT: Selectively copy job steps and their associated JOB statements.

//IEBEDITJ JOB ACCT,'',CLASS=P,MSGCLASS=T,MSGLEVEL=(1,1),NOTIFY=&SYSUID//STEP0001 EXEC PGM=IEBEDIT//SYSPRINT DD SYSOUT=*//SYSUT1 DD DSN=xxxxx.yyyyy.zzzzz,DISP=SHR//SYSUT2 DD SYSOUT=(*,INTRDR)//SYSIN DD *

EDIT TYPE=INCLUDE,STEPNAME=(STEP10,STEP5,STEP15)/*

IEBGENER: Copy records from a sequential data set, or convert a data set from sequential organization to partitioned organization.

//IEBGENER JOB ACCT,'DATA COPY',MSGCLASS=J,CLASS=A//STEP010 EXEC PGM=IEBGENER //SYSUT1 DD DSN=xxxxx.yyyyy.zzzzz,DISP=SHR //SYSUT2 DD DSN=aaaaa.bbbbb.ccccc,DISP=(,CATLG),// DCB=(RECFM=FB,LRECL=1440),SPACE=(TRK,(5,5),RLSE),// UNIT=SYSDA //SYSPRINT DD SYSOUT=*

//SYSIN DD DUMMY


IEBPTPCH: Print or punch records in a sequential or partitioned data set.

//IEBPTPCH JOB// EXEC PGM=IEBPTPCH//SYSIN DD *

PRINT MAXFLDS=2 TITLE ITEM=('Name',22),

ITEM=('GPA',50) TITLE ITEM=(' ',1)

RECORD FIELD=(25,1,,22), FIELD=(4,51,,50)/*//SYSPRINT DD SYSOUT=*//SYSUT1 DD *Person 1 307 C Meshel Hall 3.89Second person 123 Williamson Hall 2.483rd person 321 Maag Library 1.52/*

//SYSUT2 DD SYSOUT=*//

IEBUPDTE: Incorporate changes to sequential or partitioned data sets, or PDSEs.

//stepname EXEC PGM=IEUPDTE,PARM=parm //SYSPRINT DD SYSOUT=class //SYSUT1 DD ... //SYSUT2 DD ... //SYSIN DD ...

IEHINITT: IEHINITT is a system utility used to place standard volume label sets onto any number of magnetic tapes mounted on one or more tape units.

//LABEL JOB ...//STEP1 EXEC PGM=IEHINITT//SYSPRINT DD SYSOUT=A//LABEL1 DD DCB=DEN=2,UNIT=(tape,1,DEFER)//LABEL2 DD DCB=DEN=3,UNIT=(tape,1,DEFER)//SYSIN DD *LABEL1 INITT SER=TAPE1LABEL2 INITT SER=001234,NUMBTAPE=2/*

IEHLIST: IEHLIST is a system utility used to list entries in the directory of one or more partitioned data sets or PDSEs, or entries in an indexed or non-indexed volume table of contents. Any number of listings can be requested in a single execution of the program.

//VTOCLIST JOB ...//STEP1 EXEC PGM=IEHLIST//SYSPRINT DD SYSOUT=A//DD2 DD UNIT=3390,VOLUME=SER=TOTTSB,DISP=SHR


//SYSIN DD *LISTVTOC VOL=3390=TOTTSB,INDEXDSN=SYS1.VTOCIX.TOTTSB

/*

IEHMOVE: Move or copy collections of data.

//stepname EXEC PGM=IEHMOVE,PARM='LINECNT=xx,POWER=n'//SYSPRINT DD SYSOUT=class//SYSUT1 DD UNIT=aaaa,VOL=SER=bbbbbb,DISP=OLD//anyname1 DD UNIT=cccc,VOL=SER=dddddd,DISP=OLD//anyname2 DD UNIT=eeee,VOL=SER=ffffff,DISP=OLD//SYSIN DD ...

ADRDSSU: It is used for backup, restore and dump

Backup Job

//JOB Statement//STEP2 EXEC PGM=ADRDSSU //SYSPRINT DD SYSOUT=* //DSN2 DD UNIT=3490,DISP=SHR,EXPDT=99000,

// DSNAME=XXX.XXX.XXX.XXX //TAPE2 DD DSN=XXX.XXX.XXX.XXX.BKUP,UNIT=3590-1, // DISP=(NEW,CATLG,DELETE), // VOL=(,RETAIN,,20,REF=*.STEP1.TAPE1), // LABEL=(02,SL,RETPD=10) //SYSIN DD * DUMP INDD(DSN2) OUTDD(TAPE2) /*

Restore Job

//STEP3 EXEC PGM=ADRDSSU //SYSPRINT DD SYSOUT=* //DSN3 DD UNIT=3490,DISP=(NEW,CATLG,DELETE), // DSNAME=XXX.XXX.XXX.XXX,EXPDT=99000 //TAPE3 DD DSN=XXX.XXX.XXX.XXX.BKUP,UNIT=3590-1, // DISP=OLD,VOL=SER=EB0231,LABEL=(3,SL) //SYSIN DD * DUMP INDD(TAPE3) OUTDD(DSN3) /*

Physical Move

//JOB//EXEC PGM=ADRDSSU//SYSPRINT DD SYSOUT=*//FROM DD VOL=SER=XXX,DISP=SHR,UNIT,=SYSALLDA//TO DD VOL=SER=YYY,DISP=SHR,UNIT,=SYSALLDA


//SYSIN DD * COPY INDD(FROM1) OUTDD(T01) FULL ALLDATA(*) ALL EXP- TOL(IOERROR) COPYVOLID//*

Logical Move

//JOB//EXEC PGM=ADRDSSU//SYSPRINT DD SYSOUT=*//FROM DD VOL=SER=XXX,DISP=SHR,UNIT,=SYSALLDA//TO DD VOL=SER=YYY,DISP=SHR,UNIT,=SYSALLDA//SYSIN DD * COPY LOGINDD (FROM1) OUTDD (T01) TOL(IOERROR)- ALL DATA (*) ALL EXCP ADMIN PURGE-

DELETE ALL MULTI WAIT (0,0)- DS (INCL (* *), EXCL(SYS1.VTOIX.*,SYS1.VVDS.*))/*

Reclaiming DASD SpaceDASD space can be reclaimed by releasing unused space in dataset

Example:

//EXEC PGM=ADRDSSU//SYSIN DD * RELEASE- DYNAM(SMS007)- INCLUDE (XXX.**)/*

Compression

It removes unused space between members in a pds. This recovered space is then available for reuse at the end of the dataset.

Example:

//JOB, REGION=OM//SYSIN DD * COMPRESS-

DYNAM((SMS011),(SMS006),(SMS001)….) -INCLUDE (XXX.**)

/*

Consolidating Free Space On VolumesBy using DEFRAG we can consolidate the free space on volumes. This is done to prevent from out-of-space abens on new allocations.

Example:

//STEP1 DD UNIT=3390,VOL=SER=SMS001,DISP=SHR//SYSIN DD *

DEFRAG -Level II

IBM Utilities

DDNAME (STEP1)/*

Conversion Of SMS To Non-SMS Management

Dataset can be converted from sms managed to non-sms.

Example:

//DEFRAG EXEC PGM=ADRDSSU//SYSPRINT//SYSIN DD *

CONVERV -DYNAM (SMS002) -NONSMS

/*

Level II SMS and ACS Routine Functionality

DFSMSThe Primary means of managing space in Z/OS is through the DFSMS

component of the operating system. DFSMS automatically manages data from creation to expiration.The heart of DFSMS is Storage Management Subsystem (SMS)Using SMS, a storage administrator defines policies that describes,

Data Allocation CharacteristicsPerformance and Availability GoalsBackup and Retention requirementsStorage requirements for the system.

NOTE: SMS governs these policies for the system and ISMF provides the user interface for defining and maintaining the policies.

DFSMS ComponentsIt is a set of product associated with Z/OS that is responsible for data

management.DFSMS has five functional components. They are,

DFSMSdfp – Data Facility Product DFSMSdss – Data Set Services DFSMShsm – Hierarchical Storage Manager DFSMSrmm – Removable Media Manager DFSMStvs – Transactional VSAM Services

DFSMSdfp It is the base element of Z/OS It is the heart of storage management subsystem It provides the logical and physical input and output for z/OS storage It keeps track of all data and programs managed within z/OS

DFSMSdss It works on DASD volumes only in the MVS environment. It is an optional feature of Z/OS DFSMSdss helps to do,

Copy and move data sets between volumes of like and unlike device types

Dump and restore data sets, entire volumes, or specific tracks Convert data sets and volumes to and from SMS management Compress partitioned data sets Release unused space in data sets Reduce or eliminate DASD free-space fragmentation by consolidating

free space on a volume

DFSMShsm It is a tool designed to support Availability management and Space

management. Availability management is a process that helps maintain a backup copy of

data set that can be easily recovered incase of damage in the original copy or incase of accidental deletion of data set.

Space management is a process that monitors usage to maintain enough space on user volumes for new and active data.

DFSMShsm uses three level storage device hierarchies for space management.

Level 0 contains data directly accessible to the end user or program. Level 1 is disk containing data sets that DFSMShsm has moved from level 0

volumes. Level II SMS and ACS Routine

Functionality

Level 2 is tape containing data sets that DFSMShsm has moved from level 1 or level 0 volumes.

DFSMShsm can automatically delete data sets that have passed their expiration dates.

DFSMShsm can manage backed up, dumped, and migrated volumes and data sets.

DFSMSrmm It manages all the tape volumes and datasets. It manages the movement of tape volumes between libraries and vaults over the life of

the tape data sets. It also handles scratch and expired data sets.

DFSMStvs It is an optional z/OS feature that enables batch jobs and CICS online

transactions to update shared VSAM data sets concurrently. Multiple batch jobs and online transactions can be run against the same VSAM

data sets, and DFSMStvs helps ensure data integrity for concurrent batch updates while CICS ensures it for online updates.

SMS

The Dataset allocated through SMS are called System-managed DS or SMS-managed DS.

One of the mechanisms DFSMS/MVS provides to help automate storage management is the SMS constructs.

They are defined using ISMF When we allocate a Dataset to use SMS, we specify the dataset requirement

through SMS constructs. The SMS Constructs includes,

Data Class Management Class Storage Class Storage Group

NOTE: The users do not need to specify these classes because the storage administrator has set up ACS (Automatic Class Selection) routines to determine which classes are used for a given data set.

SMS CONSTRUCTS

DATA CLASSA data class contains the allocation and the space attribute for a

dataset.Data class applies to both SMS and non-SMS managed data sets. They do not apply to objects.

STORAGE CLASSStorage classes are used to define performance and availability goals.It is used to select a device that meets those goals.ACS routine can override the storage class assignment.It applies only the SMS-managed data sets and its objects.

MANAGEMENT CLASSIt applies only to SMS-managed DASD datasets and objects.It is used to define backup and retention requirements.


ACS routine can override the management class assignment.Some of the attributes that are defined in management class are:

Expiration Date Migration Criteria GDG management Backup of dataset Aggregate Backup

HINT: Management class allows us to define the management requirement for an individual dataset than for the entire volume.

STORAGE GROUPIt is a collection of logical volumes managed as a single unit.Collection includes,

DASD volumesTape Volumes

System paging volumesOptical volumesDASD, Tape, Optical volume treated a single unit.

All SMS-managed dataset must contain a storage group

SMS Configuration

SMS configuration composes:

Set of data class, storage class, and management class and storage group. ACS routines to assign classes and groups Tape Library definition Aggregate group definition Optical Library and drive definitions.

SMS configurations are stored in SMS control dataset, which is a VSAM Linear data set.Control data set must be defined before activating SMS.Different types of control data set are:

Source Control Data set (SCDS) Active Control Data set (ACDS) Communication Control Data set (COMMDS)

Source Control Data set It contains SMS classes, groups and translated ACS routines that define

storage management policies. A SMS configuration may contain more than one SCDS but only one can be

activated at a time. SCDS is never used to manage storage allocations.

Active Control Data set It is the systems active copy of the current SCDS When SMS configuration is activated, SMS copies the existing SCDS into

ACDS.


Communication Control Data set It enables communication between SMS in a multi-system environment. It contains:

SMS status Space statistics MVS status for each system-managed volumes

ACS ROUTINEThe role of the ACS routines is to assign specific policies to the data set that is

providing centralized administrator control over data set allocation. Once a DFSMS configuration has been created, it can be used as the set of policies that automate storage management across a z/OS sysplex.

Fig. Working principle of ACS Routine.


The ACS routines are invoked whenever data sets are created, either at initial allocation or as a result of operations that cause them to be reallocated or moved.

Level II Interactive Storage Management Facility

The Interactive Storage Management Facility (ISMF) helps to analyze and manage data and storage interactively. ISMF is an Interactive System Productivity Facility (ISPF) application.ISMF provides interactive access to the space management, backup, and recovery services of the DFSMShsm and DFSMSdss.

A storage administrator uses ISMF to define the installation's policy for managing storage by defining and managing SMS classes, groups, and ACS routines. ISMF then

places the configuration in an SCDS. Then SCDS activate an through ISMF or an operator command.

ISMF is a panel-driven interface. ISMF can be used to:

Display lists with information about specific data sets, DASD volumes, mountable optical volumes, and mountable tape volumes

Generate lists of data, storage, and management classes to find out how data sets are being managed

Display and manage lists saved from various ISMF applications

ISMF generates a data list based on selection criteria. Once the list is built, we can use ISMF entry panels to perform space management or backup and recovery tasks against the entries in the list.

As a user performing data management tasks against individual data sets or against lists of data sets or volumes, ISMF can use to:

Edit, browse, and sort data set records Delete data sets and backup copies Protect data sets by limiting their access Recover unused space from data sets and consolidate free space on DASD

volumes Copy data sets or DASD volumes to the same device or another device Migrate data sets to another migration level Recall data sets that have been migrated so that they can be used Back up data sets and copy entire volumes for availability purposes Recover data sets and restore DASD volumes, mountable optical volumes, or

mountable tape volumes.

ISMF: Profile option

User Mode Entry Panel


In the ISMF Profile Option Menu panel, Option 0 from the ISMF Primary Menu Change the user mode from end user to storage administrator, or from Storage Administrator to End user.

Option 1 - End User can perform very limited no of task

Option 2 - Storage administrator mode we can perform all storage administration Task.

ISMF Panel

Generating ListsWe can construct a list of information about specific data sets, volumes, or

SMSClasses.

ISMF: Data set optionData Set Selection Entry panel

Select the option 1 (Data Set) from the ISMF Primary Option Menu and specify filter criteria to get a list of data sets, as follows:

To generate a new list from criteria below

Data Set Name . . . 'MHLRES2.**'Here the data set list generated for the generic data set name MHLRES2.**

The process of selecting data sets and volumes using partial names is called Partial Qualification.


Dataset Selection Panel

Partially Qualifying Data Set Names

To qualify data set names, use asterisks and percent signs as global file-namecharacters within a qualifier:

Example

1. Use a percent sign as a global file-name character for a single position:DATA SET NAME ===> TEST%

ISMF selects data sets whose name is exactly five characters and starts with theletters TEST. This example could include TEST1 to TEST9 or TESTA to TESTZ,or both.

2. Use an asterisk as a global file-name character for zero or more characters.For example, when specify a data set name ofDATA SET NAME ===> TEST*

ISMF selects data sets whose name consists of only one qualifier and beginswith the letters TEST. This could include: TEST, TESTX, and TEST1 throughTEST1000.

3. When specifying a data set name, use a double asterisk as a global file-namecharacter for any number of qualifiers. A qualifier is one of the parts connectedby periods that constitute a data set name. A data set name consists of one ormore qualifiers.For example, when specify a partial data set name of

DATA SET NAME ===> 'SYS1.***'


ISMF selects data sets with any number of qualifiers. The first qualifier must be

SYS1. ISMF could select the following data sets:

SYS1.TEST.TESTSYS1.LIST.XMPSYS1.MEMO.EMP.A

Volume OptionPartially Qualifying DASD Volume Names

Use an asterisk sign as a global file-name character for zero or more characters.For example, when specify a partial volume serial number of VOLUME SERIAL NUMBER = SYS* ISMF lists all volume names whose first 3 characters are SYS. The list might include SYS1, SYSA, SYS, or SYSLIB.

To generate a list of DASD volumes, select option 1 to displays the first of three pages of the Volume Selection Entry Panel.


Volume serial number

Enter a full or partial serial number of the volume or volumes to include in the list.Use this optional field to restrict the list to volumes with a specific volume serial number or range of volume serial numbers. To include a single volume, enter a fully qualified volume serial number of one to six characters:

Example

VOLUME SERIAL NUMBER ===> SYS001

To include a range of volumes, enter a partially qualified volume serialnumber by using a single asterisk as a global file-name character:

VOLUME SERIAL NUMBER ===> SYS *

Use six asterisks to specify the system residence volume (SYSRES):

VOLUME SERIAL NUMBER ===> *****

Use a single asterisk to specify all mounted volumes that fit otherselection criteria:

VOLUME SERIAL NUMBER ===> *

ISMF: Management Class option

By using the management class for a given data set, DFSMShsm can decide howdata sets should be backed up, when they should be migrated, and when backupcopies should be deleted.

Management class option is use to display, modify,and define options for the SMS management classes

A management class defines the following attributes:

1. Partial Release2. Expiration Attributes3. Expire After Date/Days4. Expire After Days Non-Usage5. Retention Limit6. Migration Attributes7. Command or Auto Migrate8. Level 1 Days Non-Usage9. Primary Days Non-Usage10. Generation Data Group Management Attributes11. Number of GDG Elements on Primary12. Rolled-off GDS Action13. Backup Attributes14. Administrator or User Command Backup Versions


15. Auto Backup16. Backup Copy Technique17. Backup Frequency18. Number of Backups (Data Set Deleted)19. Number of Backups (Data Set Exists)20. Retain Days Extra Backups21. Retain Days Only Backup Versions22. Class Transition Attributes23. Object Class Transition Criteria24. Aggregate Backup25. Abackup Copy Technique26. Copy Serialization27. Number of Versions28. Retain Extra Versions29. Retain Extra Versions Unit30. Retain Only Version31. Retain Only Version Unit

Data Class option

A data class defines the way data sets are allocated

Data class attributes are assigned to a data set when the data set is created. It can applicable to both SMS-managed and non-SMS-managed data sets

A data class defines the following attributes:

1. Compaction2. Data Set Organization3. Record Format4. Record Size5. Key Length/Offset6. Space7. Average Record8. Average Value9. Primary10. Secondary11. Directory12. Data Set Name Type13. Media Type14. Recording Technology15. Retention Period or Expiration Date16. Volume Count17. Additional Volume Amount18. Imbed19. Replicate20. Control Interval Size21. Percent Free Space22. Share Options


Storage ClassThe Storage Class lets the storage administrator specify performance

objectives and availability attributes to a collection of data sets.

A storage class defines the following attributes:

1. Storage Class Name2. Description3. Performance Objectives4. Direct Bias5. Direct Millisecond Response6. Initial Response Seconds7. Sequential Bias8. Sequential Millisecond Response9. Sustained Data Rate10. Availability Objectives11. Accessibility12. Availability13. Guaranteed Space

Storage group

Storage Group (SG). A collection of storage volumes and attributes, The collections can be a group of DASD volumes or tape volumes, or a group of DASD volumes and optical volumes. Storage Group should be one to eight character, it should be alphabetic or national character.

Automatic Class Selection

1. Edit - Edit ACS Routine source code 2. Translate - Translate ACS Routines to ACS Object Form 3. Validate - Validate ACS Routines Against Storage Constructs 4. Test - Define/Alter Test Cases and Test ACS Routines 5. Display - Display ACS Object Information 6. Delete - Delete an ACS Object from a Source Control Data Set

Automatic class selection (ACS) routines to assign classes(Data, storage, and management) and storage group definitions to data sets, Database data and objects.

ACS language, which is a high-level programming language.Once written, ACS translator to translate the routines to object form so they canbe stored in the SMS configuration.

The ACS language contains a number of read-only variables, which can use to analyze new data allocations.


SMS configuration

An SMS configuration is composed of:

1. A set of data class, management class, storage class, and storage group2. ACS routines to assign the classes and groups3. Optical library and drive definitions4. Tape library definitions5. Aggregate group definitions6. SMS base configuration, that contains information such as:

I. Default management class II.Default device geometry III.The systems in the installation for which the subsystem manages storage.

The SMS configuration is stored in SMS control data sets, which are VSAM linear data sets.

Define the control data sets before activating SMS. SMS uses the following types ofcontrol data sets:

SMS control data setsSMS stores its class and group definitions, translated ACS routines, and

system information in three control data sets.

Source Control Data Set (SCDS)The SCDS contains SMS classes, groups, and translated ACS routines that

define a single storage management policy, called an SMS configuration. Even though system has several SCDSs, but only one can be used to activate the SMS configuration.

SCDS should have gone through test , before activating a configuration, retain at least one prior configuration needed to avoid problem . The SCDS is never used to manage allocations.

Active Control Data Set (ACDS)The ACDS is the system's active copy of the current SCDS. When activate a

configuration, SMS copies the existing configuration from the specified SCDS into the ACDS.

By using copies of the SMS classes, groups, volumes, optical libraries, optical drives, tape libraries, and ACS routines rather than the originals, The changes should be done in the current storage management policy without disrupting the original

For example, while SMS uses the ACDS, The following action can be done:

1.Create a copy of the ACDS2.Create a backup copy of an SCDS3Modify an SCDS4.Define a new SCDS


Communications Data Set (COMMDS)The COMMDS data set contains the name of the ACDS and storage group

volume statistics. It enables communication between SMS systems in a multisystem environment.

1. Source Control Data Set (SCDS)2. Active Control Data Set (ACDS)3. Communications Data Set (COMMDS)

CDS Panel

CDS Name . . ACTIVE (1 to 44 Character Data Set Name or 'Active') Select one of the following Options: 1. Display - Display the Base Configuration 2. Define - Define the Base Configuration 3. Alter - Alter the Base Configuration 4. Validate - Validate the SCDS 5. Activate - Activate the CDS 6. Cache Display - Display CF Cache Structure Names for all CF Cache Sets 7. Cache Update - Define/Alter/Delete CF Cache Sets

EditThrough this panel ACS source code can be modified or change based on our requirement.

Translate The translation process checks the routines for syntax errors and converts the code into an ACS object. If the code translates without any syntax errors, then the ACS object is stored in the SCDS.

Validate When validate the SCDS, verify all classes and groups assigned by

ACS routines are defined in the SCDS. To validate the SCDS:

From the ISMF Primary Option Menu panel, select Control Data Set and press Enter

Enter SCDS data set name and select 4 Validate.

Activate Activating a new SMS configuration means to copy the configuration from

SCDS to ACDS.To activating an SMS configuration from ISMF :

From the ISMF Primary Option Menu panel, select Control Data Set.

In the CDS Application Selection panel, enter SCDS data set name and select 5 Activate.

Test From this panel we can test ACS routine, whether the given class works fine or

not.


Aggregate groupAggregate group is a collection of related data sets and control

information that has been pooled to meet a defined backup or recovery strategy. If a disaster occurs, use these backups at a remote or local site to recover critical applications.

The aggregate group application allows to:

1. Generate a list of aggregate groups.2. Display the attributes of a single aggregate group.3. Delete aggregate groups.4. Edit and browse the selection data sets associated with an aggregate group.5. Edit and browse the instruction data sets associated with an aggregate group.6. Backup the selected aggregate group.7. Recover an aggregate group that has been backed up.8. Specify the number of local copies of aggregate backup (ABACKUP) output

files that is to be created. (15 maximum)9. Assign aggregate backup attributes to an aggregate group by giving it a10. management class name

Removable Media Manager

1 Optical Library - Optical Library Configuration2 Optical Drive - Optical Drive Configuration 3 Tape Library - Tape Library Configuration

We can list out Optical library, Optical Drive and Tape library information from Removable media manager option.

Level II Review of Storage Pools to Determine Space Issues

Go to ISMF panel and select storage group option A list of storage group names will be shown Check for the %freespace for the entire storage group Document the %freespace details against every storage group Examine the minimum %freespace If the %freespace falls down the threshold value (i.e. minimum freespace), take

measures accordingly. Some of the possible measures

Adding a new volume to the existing storage group which has less %freespace

Deleting the expired data sets of the volume

Basics of Mainframes

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