//MYJOB JOB ...

//SORTIT EXEC PGM=SORT

//SYSOUT DD SYSOUT=*

//SORTIN DD DSN=...

//SORTOUT DD DSN=...

//SYSIN DD *

SORT FIELDS=(5,4,CH,A)

/*

The JCL statements you will commonly need when migrating are:

JOB: Must be the first statement for a job.

EXEC: Must be the first statement for a step. Specifies the program to be executed. For DFSORT steps, use PGM=SORT or PGM=ICEMAN.

SYSOUT DD: Defines DFSORTs message data set. DFSORT can write informational, error and diagnostic messages to this data set as directed.

SORTIN DD: Defines one or more input data sets for a sort or copy application. Multiple input data sets can be specified using OS/390s data set concatenation facility.

SORTINnn DD: Defines a data set for a merge application. SORTIN01 through SORTIN99 can each be used to specify a data set to be merged.

SORTOUT DD: Defines the output data set for a sort, merge or copy application.

SYSIN DD: Contains DFSORT control statements, comment statements and blank statements.

Other JCL statements you may need when migrating are:

JOBLIB DD: Defines the library containing the DFSORT program. Used for all steps in the job. The JOBLIB DD is only needed if the DFSORT library is not known to the operating system.

STEPLIB DD: Defines the library containing the DFSORT program. Used for a particular step in the job. The STEPLIB DD is only needed if the DFSORT library is not known to the operating system.

SORTWKnn DD: Defines a work data set for a sort application. It is recommended that you use DFSORTs dynamic allocation facility instead of specifying SORTWKnn DD statements. DFSORTs shipped defaults result in the automatic use of dynamic allocation when appropriate.

SORTDIAG DD: Forces DFSORT to print all messages and control statements in the message data set. Only needed for diagnosing problems.

SYSUDUMP DD: Defines the data set for a dump. Only needed for diagnosing problems.

376VSE to OS/390 Migration Workbook

Page 400
Image 400
IBM manual VSE to OS/390 Migration Workbook

OS/390 specifications

IBM OS/390, a versatile operating system, was a cornerstone in enterprise environments and played a pivotal role in mainframe computing. Released in the mid-1990s, OS/390 combined the strengths of IBM's MVS (Multiple Virtual Storage) with new features and enhancements, targeting scalability, reliability, and performance in demanding business applications.

One of the key features of OS/390 was its robust support for multiple users and processes. The system allowed thousands of concurrent users to access applications and data, ensuring high availability and minimizing downtime—a critical requirement for many large organizations. This scalability was supported through various enhancements in memory management and processor scheduling, enabling optimal resource allocation across diverse workloads.

OS/390 was known for its superior workload management capabilities. The Workload Manager (WLM) component allowed administrators to define service policies, specifying how system resources would be allocated according to the priority of tasks. This ensured that critical business processes received the necessary resources while less critical tasks were managed more flexibly.

Another significant characteristic of OS/390 was its commitment to security. The operating system provided comprehensive security features, including user authentication, data encryption, and auditing capabilities. This focus on security was vital for organizations handling sensitive data, ensuring compliance with regulations and safeguarding against unauthorized access.

OS/390 also supported advanced technologies that facilitated integration and development. The system included features like the IBM CICS (Customer Information Control System) for transaction processing and IMS (Information Management System) for database management. These technologies allowed organizations to build robust, high-performance applications tailored to specific business needs.

The ease of network integration was another strength of OS/390. With the advent of the Internet and global connectivity, OS/390 systems could easily interface with various network protocols, enabling businesses to operate in a connected world. This inclusion paved the way for many organizations to expand their capabilities and offer new services, driving digital transformation.

In conclusion, IBM OS/390 represented a significant advancement in mainframe technology, combining scalability, security, and robust workload management. Its rich feature set and support for critical enterprise applications solidified its role as a vital component of many organizations' IT infrastructures, ensuring they could meet their operational challenges head-on while supporting future growth. As technology continues to evolve, the legacy of OS/390 remains influential in the realm of computing.