Data Base/Data Communication (DB/DC) programs that use VSAM and non-V SAM DASD access methods (BSAM, QSAM, BPAM, BDAM, and XDAP), or EXCP, and IBM supplied OPEN/CLOSE/EOV can operate in a computing system containing the Mass Storage System with very little if any
modification. What modifications that have to be made are peculiar to the particular Data Base/Data Communication program you may be using.
The Mass Storage System is intended primarily for batch and certain response insensitive online environments. It is not intended for response oriented, interactive Data Base/Data Communication environments where having less real DASD space than needed degrades the transaction response time. The Mass Storage System is further not intended for permanent storage for Data Base/Data Communication programs. Program loading is itself a significant performance requirement and should not be degraded by Mass Storage System access times.
This section describes some of the things you should consider when two particular DB/DC programs are used in a system that contains the Mass Storage System.
If you are already using either of the IBM Data Base/Data Communication program products; Information Management System (IMS/VS) or Customer Information Control System (CICS/VS), there are special considerations you must give to planning for a Mass Storage System. The presence of the Mass Storage System can affect your Data Base/Data Communication activity whether or not the Mass Storage System actually houses the Data Base/Data Communication data bases.
Your Time Sharing Option (TSO) programs can operate with the Mass Storage System without any modification of your existing Time Sharing Option data. Foreground jobs still execute in the same manner as they do in a system that does not contain the Mass Storage System, provided that data sets are on real volumes. However, when archived data sets are used, these data sets can be on mass storage volumes.
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Background jobs will be handled the same as in a system that does not contain the Mass Storage System. When the background job is finished with the data, the data is archived in the Mass Storage System. This means that you must have real drives to be used by Time Sharing Option data and that in the transfer of data to and from the Mass Storage System and Time Sharing Option drives, the CPU channels are used.
TSO Archive Procedure Prerequisite
Setting Up Archive Procedures
You can establish a TSO CLIST containing the commands necessary to submit a job to perform the archive or retrieve function through the use of a data set copy. A familiarity with the following OS/VS2 Time Sharing Option commands and associated function, OS/VS2 lCL, and utilities is required:
• EXEC command, to execute a command procedure.
• ED IT command.
• SUBMIT command, as a subcommand of the EDIT command.
• LISTDS/LISTCAT /DELETE commands, for identification of archived data sets and to clean up working or current storage.
• IEBCOPY, which is a system data set utility for partitioned data set copy.
These publications provide information on Time Sharing Option and OS/VS utilities: OS/VS2 TSO Command Language Reference, OS/VS2 TSO Terminal
Users Guide, OS/VS2 JCL, and OS/VS Utilities.
The use of an archive procedure requires the creation of a command procedure data set using the Time Sharing Option Editor. This procedure is ultimately executed through the use of the EXEC command, causing (under EXEC control) an EDIT and a SUBMIT of an OS/VS lOB to perform the archive copying function when the background job is executed. You can get a notification of job completion by specifying the NOTIFY keyword on your SUBMIT command.
You must decide on the the following parameters that are substitutable in the CLIST through the use of a PROC statement.
• Data Set Naming. You must establish a naming convention using the same or a similar naming convention normally used for your Time Sharing Option data (such as, userid.TEXT A.TEXT). The from and to data sets can be specified at the time that the EXEC command is issued.
• Volumes. In copying from and to the archive on mass storage volumes, the volume serial number or MSVGP parameter only has to be specified for the allocation of new data sets. All old data sets are cataloged to the Master or Private catalogs.
The input statements for your CLIST should consist of:
• The PROC statement
• The use of CLIST SET, GLOBAL, GO TO, and SKIP statements and READ or WRITE statements to generate the correct job control language and prompt and/or notify the Time Sharing Option terminal user during
)
• The job control language statements entered in EDIT mode. As an example,
"//STEP EXEC PGM=IEBCOPY ' I
can be used to specify job control language for the data set copy utility or other copy programs. The substitution for data set names, volume serials, MSVGP, and other chosen variables should be noted. For example,
"//DDIN DD DSN=&FROMDS,DISP=OLD ' I
• A SUBMIT statement to cause the job being edited to be submitted to the batch processor when the command procedure is executed
• Two END commands to get out of EDIT mode and to terminate the command procedure
The Time Sharing Option OUTPUT command can optionally be used to print the job control language and messages of the job at the user's terminal when the job has completed.
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