Chapter 18 Three Operating Systems

1. Chapter 18Three Operating Systems The Architecture of Computer Hardware and Systems Software: An Information Technology Approach 3rd Edition, Irv Englander John Wiley and Sons 2003

2. Three Operating Systems • Microsoft Windows 2000/XP • UNIX and Linux • IBM zSeries z/OS Chapter 18 Three Operating Systems

3. Microsoft Windows 2000/XP • Design Goals • Operating System Features • User Environment • Desktop Components • Windows 2000/XP Architecture • Overview • System Block Diagram • Logical Memory Map Chapter 18 Three Operating Systems

4. Design Goals • Extensibility • Object-based modular design • Portability • Written in C and C++ to facilitate porting to other CPUs • Reliability • Kernel architecture design to protect from internal errors and buggy application programs • Downward compatibility • Compatible with earlier versions of Windows and DOS • Scalability and Performance • Supports symmetric multiprocessing Chapter 18 Three Operating Systems

5. 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 conservation • Manageable and secure file system with built-in recoverability options and is downwardly compatible • API that provides a wide range of services to simplify application development and ensure consistency • Built-in networking and a new distributed file system • Network server capabilities Chapter 18 Three Operating Systems

6. 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 Chapter 18 Three Operating Systems

7. Desktop Components Chapter 18 Three Operating Systems

8. 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 Chapter 18 Three Operating Systems

9. Executive Layer • Object manager • Provides standardized interface for objects • Process manager • Virtual memory manager • I/O manager • 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 Chapter 18 Three Operating Systems

10. Overview of Windows 2000 Chapter 18 Three Operating Systems

11. System Block Diagram Chapter 18 Three Operating Systems

12. Logical Memory Map Chapter 18 Three Operating Systems

13. UNIX and Linux • Design Goals • Pioneering Design Features • Operating System Features • User Environment • General Organization • Kernel operations Chapter 18 Three Operating Systems

14. 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 Chapter 18 Three Operating Systems

15. Pioneering OS Design Features • Process creation and control • Separate shell for user interface • Hierarchical directory file system • Ability to combine small independent software modules to accomplish a more complex task Chapter 18 Three Operating Systems

16. 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 Chapter 18 Three Operating Systems

17. User Environment • Login • User name and password • Start-up file for user environment customizations • System, group, and user protections are set • Interface shells • Bourne shell, C shell, and Korn shell are the most commonly used • Command line prompt • X-Windows interface • Logins to remote UNIX computers Chapter 18 Three Operating Systems

18. General Organization of a UNIX System Chapter 18 Three Operating Systems

19. Kernel Operations • Virtual storage and memory management • Process management • File management • I/O management • Networking and communication Chapter 18 Three Operating Systems

20. Virtual Address Space for a Process Chapter 18 Three Operating Systems

21. IBM zSeries z/OS • Design Goals • Operating System Services • User Environment • User Interfaces • MVS Organization • Virtual Memory Map for a Task • Data Management Chapter 18 Three Operating Systems

22. Design Goals • Maximize system performance and availability • Maximize amount of processing by providing support for execution of batch programs • Minimize operator support effort • Reliability • Security Chapter 18 Three Operating Systems

23. Virtual File System vs.Socket Layered Structure Chapter 18 Three Operating Systems

24. 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 an error or failure • System support programs and facilities • Security services • Large-scale cluster support Chapter 18 Three Operating Systems

25. 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 Chapter 18 Three Operating Systems

26. User Interfaces Chapter 18 Three Operating Systems

27. MVS Organization Chapter 18 Three Operating Systems

28. Virtual Memory Map for a Task Chapter 18 Three Operating Systems

29. Data Management • Data sets • z/OS files • Sequential, random, or indexed sequential access • Fixed or variable size • Partitioned • Directory • Members - group of independent, related records • Catalogs • z/OS directories • Master catalog for the system • VTOC – catalog for a DASD (disk) device • User catalog has an indexed entry in the master catalog Chapter 18 Three Operating Systems

30. Steps in Location of a Data Set Chapter 18 Three Operating Systems