The architecture of computer hardware and systems software an information technology approach ch18

Operating System Features Single user 32-bit or 64-bit, pre-emptive multi-tasking operating system  Powerful GUI that behaves consistently for local, network, and Internet use  Suppor

Chapter 18

Three Operating Systems

The Architecture of Computer Hardware

and Systems Software:

An Information Technology Approach

3rd Edition, Irv Englander John Wiley and Sons 2003

Three Operating Systems

 System Block Diagram

 Logical Memory Map

 Compatible with earlier versions of Windows and DOS

 Scalability and Performance

 Supports symmetric multiprocessing

Operating System Features

 Single user 32-bit or 64-bit, pre-emptive multi-tasking operating system

 Powerful GUI that behaves consistently for local, network, and Internet use

 Support for new capabilities

 Multimedia, plug-and-play hardware, electrical power

 Built-in networking and a new distributed file system

 Network server capabilities

User Environment

 Simple for novice, powerful for advanced user

 Tools, operations and applications that use the API behave in a consistent manner

 Extensive context-sensitive help

 User’s system parameters are modifiable

 Applications and users have access to the

same services and interface features

 Tools and operations perform reasonably and

in an intuitive manner

Desktop Components

Windows 2000/XP Architecture

 Modified microkernel-based

 User mode

 Environmental subsystems

 Expose OS services to the user through an API

 System support processes

 Logon and user session management

 Server processes

 Protected (kernel) mode

 Hardware abstraction layer

 Kernel

 Executive layer

 Security reference monitor

 All protected objects are monitored

 Enforces validation procedures and audits

 Local Procedure Call (LPC)

 Control of all service requests and interprocess activities

 Windowing and Graphics System

 Manages Windows graphics

 Provides Windows screen interface tools

Overview of Windows 2000

System Block Diagram

Logical Memory Map

UNIX and Linux

 Kernel operations

Design Goals

 Easy-to-use, interactive, powerful, and flexible

interface

 Powerful programming tools

 Compilers and associated tools

 Use of small, simple utility programs to perform tasks and to construct more complex applications

 Small and simple kernel together with a separate

interface shell

 Logical file system

 Multi-tasking and multiuser capabilities

 Simple system portability

Pioneering OS Design Features

software modules to accomplish a more complex task

Operating System Features

 Preemptive multitasking with multiuser

capability, automatic scheduling, and

background execution

 User shells that provide an interactive

interface, commands, and programming tools

 Interactive process creation and management

 Hierarchical, tree-based file system

 Kernel

 Network administration tools

User Environment

 Login

 User name and password

 Start-up file for user environment customizations

 System, group, and user protections are set

General Organization of a

UNIX System

Virtual Address Space for a

Process

IBM zSeries z/OS

Design Goals

availability

providing support for execution of batch programs

Virtual File System vs.

Socket Layered Structure

Operating System Services

 Sophisticated resource allocation services and workload

management

 Data set management services

 Job and task management

 Virtual storage operation and management

 Network services

 Time-sharing support

 System resource logging, auditing and accounting

 Error detection, recovery, and logging

 Reassignment of tasks and data to other resources in the event of

User Environment

 BCP, Base Control Program

 JCL, Job Control Language

 TSO, Time Sharing Option

 Used for program development and job preparation

 JES, Job Entry Subsystem

 Job submissions

 ISPF, Interactive System Productivity Facility

 Menu-driven facility that serves as an extension to TSO

 CICS, Customer Information Control System

 Application enabler that provides services to application

programs that have been developed to work with it

 UNIX

User Interfaces

MVS Organization

Virtual Memory Map for a Task

Data Management

 Data sets

 z/OS files

 Sequential, random, or indexed sequential access

 Fixed or variable size

 Master catalog for the system

 VTOC – catalog for a DASD (disk) device

 User catalog has an indexed entry in the master catalog

Steps in Location of a Data Set