U

 

V

 

 

UCS naming conventions

218

variables 73

 

 

understanding device allocation 448

vendor applications

154

understanding operational differences 242

verifying new OS/390 system 413

understanding the operator interfaces

VersionMatch/SRC

526

controlling consoles

444

VIRTAD macro

290

 

extended MCS consoles

virtual storage

5

 

using SDSF for system operation 446

considerations for MVS 135

 

using the TSO/E functions 445

constraint

5

 

 

 

managing display consoles

macros 289

 

 

 

console modes

444

VM systems

421

 

 

 

display areas

445

VM, LPAR, or Stand-alone Systems

421

PFKeys

445

 

VM, LPAR, or Standalone Systems

 

understanding message formats and Replies 446

logical partitioning

422

 

unit address

80

 

our recommendation

 

 

unit testing

511

 

new users of VM

425

 

unlabeled tapes 105

OS/390 guest considerations

430

UNLOAD 339

 

shared DASD

425

 

unloading database

176

use of CMS

429

 

 

unsupported

 

 

software partitioning

423

 

linkages

338

 

summary

430

 

 

 

P/I options in MVS

339

VM/ESA environment

370

products in CICS TS

136

VM/ESA Guest support

29, 426

statements 346

 

VOLSEQ 339

 

 

UPSI 82, 149, 174, 255, 275, 276

volume cleanup

124

 

user

 

volume interchangeability 103, 108

Assembler exits 364

volume ownership

120

catalogs 115

 

VS COBOL II 355

 

descriptions 178

& COBOL for VSE/ESA reserved words 265

hardcopy library 412

CICS programs

259

labels 105

compiler options

261

name

547

 

VS FORTRAN in OS/390

349

profiles 155

 

VSAM 97

 

 

 

program communication bytes 275

accessing VSE catalog from OS/390 118

program switch indicators (UPSI) 275

additional MVS SHOWCB fields 292

softcopy library

412

AMS commands

121

written applications 195

BACKUP/RESTORE

124, 387

written TCP/IP applications 195

catalog

81, 110, 112

using

 

 

catalog conversion

118

BSD/C sockets

196

catalog moving

119

 

BTAM

193

 

CHECK macro

292

 

CMS

429

 

CISIZEs

122

 

 

command procedures

163

 

converting VSE catalogs to OS/390 ICF

IPCS

474

 

 

 

catalogs

118

 

 

 

 

ISPF utilities 439

 

 

cross-system shareoptions

129

SDSF for operators

441

 

data set naming conventions

550

SDSF for system operation

446

data set sharing alternatives

130

SDSF panels for NJE

454

 

default models

123

 

 

 

SDSF panels for RJE

453

 

differences 110

 

 

 

 

sockets API for Assembler

196

error & reason code compatibility 131

the Preprocessor API

196

 

error compatibility

292

 

TSO/E functions

445

 

 

EXAMINE command

477

 

using the system

158

 

 

functional differences

119

 

accessing the system

159

 

IDCAMS

455

 

 

 

 

entering and manipulating data 159

implicit DEFINE

123

 

 

utilities

173, 180, 393, 439

 

introduction to differences 110

 

 

 

 

 

KSDS structural errors

477

 

 

 

 

 

 

macros

290

 

 

 

 

618VSE to OS/390 Migration Workbook

Page 642
Image 642
IBM OS/390 manual VS Cobol II, Vsam, Backup/Restore, Btam, Cms

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.