/XRL/5

 

69

Chapter 4, Job Control Language (JCL) Differences and

 

 

Considerations

 

 

209, 375, 482

JCLFIL

2043CH04

 

 

69

4.1, The Philosophy of JCL in System/390

 

 

69, 73

JCLHI

2043CH04

 

 

72

4.2, High Level Similarities

 

 

69

CONJCL1

2043CH04

 

 

73

4.2.1.9, Conditional JCL

JCLDIFF

2043CH04

 

 

73

4.3, JCL Differences Between VSE and MVS

 

 

69

JCLRED

2043CH04

 

 

76

4.3.2, JCL Expansion

CONJCL2

2043CH04

 

 

84

4.3.11.3, MVS Conditional JCL

 

 

73

JECL

2043CH04

 

 

89

4.4, JECL

 

 

69, 84

JCLCOMP

2043CH04

 

 

91

4.5, VSE and MVS JCL Comparison Example

 

 

69

VSESAM

2043CH04

 

 

92

4.5.1, Sample VSE JCL

 

 

77, 91, 91

MVSSAM

2043CH04

 

 

93

4.5.2, Sample MVS JCL

 

 

91, 91

VSECARR

2043CH04

 

 

94

4.5.3, Sample VSE plus Carry-Over

 

 

79, 91, 91

TDSTOR

2043CH05

 

 

97

Chapter 5, Disk and Tape Storage Considerations

 

 

84, 404

DTAMSD

2043CH05

 

 

97

5.1, Access Method Similarities and Differences

 

 

97

DTNAME

2043CH05

 

 

99

5.2, Data Set Naming Considerations

 

 

97, 481

DTMGT

2043CH05

 

 

100

5.3, Storage and Space Management

 

 

97

DTTAPE

2043CH05

 

 

103

5.4, Tape Similarities and Differences

 

 

97

DTDISK

2043CH05

 

 

108

5.5, DASD Similarities and Differences

 

 

97

IVTOC

2043CH05

 

 

109

5.5.3, Indexed VTOC Considerations (OS/390)

 

 

108

DTVSAM

2043CH05

 

 

110

5.6, VSAM Differences

 

 

97, 175

VSCATS

2043CH05

 

 

112

5.6.2.2, VSAM Catalogs

VSCATCM

2043CH05

 

 

117

5.6.4, OS/390 - VSE/VSAM Catalog Compatibility

 

 

110

ACCATM

2043CH05

 

 

118

5.6.4.1, Accessing a VSE/VSAM Catalog from an OS/390

 

 

System

 

 

112

IRDSNS

2043CH05

 

 

128

Intra-Region Data Set Name Sharing

 

 

128

CSDSHAR

2043CH05

 

 

129

5.6.6.3, Cross-System and DASD Sharing

 

 

118

CICS

2043CH06

 

 

133

Chapter 6, CICS

 

 

17, 17

CICSDLI

2043CH06

 

 

154

6.2, CICS with DL/I

ICCFTSO

2043CH07

 

 

155

Chapter 7, ICCF and TSO

 

 

17, 17, 18, 18

TSOESUB

2043CH07

 

 

162

7.4, Submitting Jobs for Batch Execution

 

 

212

DB2DLI

2043CH08

 

Page 651
Image 651
IBM OS/390 manual XRL/5

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.