Operaringvsystem Operating_System_Structure.pptx

Operatingvsystem System_Programs_in_OS_3rd_Sem

1. Operating System Structure Overview of different OS architectures

2. What is an Operating System Structure? The structure of an Operating System (OS) defines how its components are organized and interact. It determines how key functions like process management, memory management, and I/O are implemented.

3. Objectives of OS Structure • Efficient management of system resources • Provides user interface to interact with hardware • Ensures system security and stability • Organizes OS components for performance

4. Types of OS Structures 1. Monolithic Structure 2. Layered Structure 3. Microkernel Structure 4. Modular Structure 5. Hybrid Structure

5. Monolithic Structure • All OS functions combined into a single large program. • Direct communication between all modules. Examples: MS-DOS, early UNIX. Advantages: - Fast execution - Simple design Disadvantages: - Hard to debug - Poor security

6. Layered Structure • OS divided into multiple layers. • Each layer interacts only with adjacent layers. Example: THE OS, UNIX (partially layered). Advantages: - Easy debugging and maintenance Disadvantages: - Slower due to multiple layers

7. Microkernel Structure • Only essential services (IPC, scheduling) run in kernel. • Other services run in user mode. Examples: Mach, QNX, Minix. Advantages: - High security and reliability Disadvantages: - Slower due to message passing

8. Modular Structure • OS divided into independent modules. • Modules can be loaded/unloaded dynamically. Examples: Modern UNIX, Linux. Advantages: - Flexible and easy maintenance

9. Hybrid Structure • Combines features of monolithic, microkernel, and modular systems. • Used in modern OS. Examples: Windows, macOS, Android. Advantages: - High performance, flexibility, and security.

10. Comparison of OS Structures Monolithic: Fast but less secure Layered: Well organized, moderate speed Microkernel: Secure, slower Modular: Fast and flexible Hybrid: Combines best of all