VSAM (continued) managed SAM files 122 managed space 15

moving catalog to different DASD type 119 MVS VSAM CHECK macro 292 NOALLOCATION data sets 123

OS/390 Backup/Restore 387 catalog management 114 cross-region SHR(4) 127

cross-system shareoptions 129 master catalog 114

user catalogs 115

VSE catalog compatibility 117 programming language support 131 reason code compatibility 292 record sizes 122

relocating catalog 119 REPRO function 119 SHAREOPTIONS 125 TCLOSE 292

VSE Backup/Restore 387 VSE TCLOSE macro 292 VSE/VSAM access from OS/390 118

VSAM differences

data sharing & integrity

alternatives to VSAM data set sharing 130 cross-region sharing - single CPU

environment 126

cross-system & DASD sharing 129 DASD Sharing considerations 130 intra-region data set name sharing 128 OS/390 definitions for DASD sharing

support 129

OS/390 VSAM cross-region SHR(4) 127 OS/390 VSAM cross-system Shareoptions 129 SHAREOPTIONS (X 3) 130 SHAREOPTIONS (X 4) 130

single ACB OPEN - multiple string processing 128

single region data set sharing 128 DFSORT and VSAM considerations 131 error & reason code compatibility 131 introduction 110

OS/390 - VSE/VSAM catalog compatibility accessing a VSE/VSAM catalog from an OS/390

system 118

converting VSE/VSAM catalogs to OS/390 ICF catalogs 118

moving a VSAM catalog to a different DASD Type 119

OS/390 catalogs

Integrated Catalog Facility (ICF) 111 management 114

master catalog 114 user catalogs 115 VSAM catalogs 112

programming languages support Assembler 131

VSAM differences (continued)

programming languages support (continued)

COBOL for OS/390 & VM

131

 

OS/VS COBOL

131

 

 

 

 

PL/I

131

 

 

 

 

 

 

 

 

RPG

131

 

 

 

 

 

 

 

VSAM functional differences

 

 

AMS commands

121

 

 

 

areas of consideration

119

 

catalog structures

 

120

 

 

 

COMPRESS

121

 

 

 

 

 

default models

123

 

 

 

DELETE IGNOREERROR

121

 

FBA DASD

120

 

 

 

 

 

IKQVCHK - catalog check

125

 

IKQVDU - volume cleanup

124

 

JCL implicit DEFINE

123

 

 

NOALLOCATION data sets

123

 

NOIMBED option

120

 

 

 

partition independent file names

124

reusable data sets

 

123

 

 

shared volume ownership

120

 

space classes

125

 

 

 

 

SYNCHK parameter

121

 

 

VSAM CI and record sizes

122

 

VSAM SHAREOPTIONS

125

 

VSE/VSAM BACKUP/RESTORE & VSE

FASTCOPY

124

 

 

 

 

 

VSE/VSAM-managed SAM files

122

XXL KSDS

121

 

 

 

 

 

 

VSE

 

 

 

 

 

 

 

 

 

and MVS JCL

86

 

 

 

 

 

 

ASSGN statement

80, 83

 

 

 

carry-over

79, 94

 

 

 

 

 

 

COBOL compilers conversion considerations 259

communication region

274

 

 

data management macros

292

 

data set naming 99

 

 

 

 

 

DATE function

81

 

 

 

 

 

 

FASTCOPY

124

 

 

 

 

 

 

Interactive Interface

151

 

 

 

JCL - sample

92

 

 

 

 

 

 

JCL Analyzer

79

 

 

 

 

 

 

JCL statements

82

 

 

 

 

 

JCL versus MVS JCL

 

73

 

 

 

Job Control statements

82

 

 

LISTLOG utility program

393

 

logical unit address

80

 

 

 

multitasking macros

283

 

 

 

OS/390 (vs. cloned DASD)

433

 

OS/390 application synchronization

430

positioning

502

 

 

 

 

 

 

printer Parm macro

241

 

 

 

PRINTLOG utility

393

 

 

 

 

risky coding practices

 

504

 

 

storage management

 

100

 

 

to OS/390 migration considerations

250, 352

UPSI

82

 

 

 

 

 

 

 

 

Index 619

Page 643
Image 643
IBM OS/390 OS/VS Cobol, Compress, Delete Ignoreerror, Vsam Shareoptions, Vse/Vsam Backup/Restore & Vse, Fastcopy, XXL Ksds

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.