Operating System
OS Part-1
OS Part-2
- File Concepts and Access methods
- Free Space Management and Allocation methods
- Directory Systems and Protection
- File Organization, Sharing and Implementation issues
- Disk and Drum Scheduling
- I/O Devices Organisation & I/O Buffering
- I/O Hardware, Kernel I/O subsystem and Transforming I/O Requests to Hardware Operations
- Device Drivers and Path Management
- Device Driver Sub Modules and Procedure
- Device Scheduler and Handler
- Interrupt Service Routine (ISR)
- File System in Linux and Windows
OS Part-3
- Process and Process Control Block(PCB)
- Process Scheduling( Preemptive and Non Preemptive)
- Scheduling Algorithms
- Algorithm Evaluation
- Multiple Processor Scheduling
- Real Time Scheduling
- Operations on Processes
- Threads
- Inter-Process Communication
- Precedence Graphs
- Critical Section Problem
- Semaphores
- Classical Problems of Synchronization
- DeadLock
- Deadlock Prevention and Avoidance
- Deadlock Detection and Recovery
- Process Management in Linux
OS Part-4
- Memory Hierarchy in OS
- Concepts of Memory Management
- MFT and MVT
- Logical and Physical Address Space
- Swapping
- Contiguous and Non Contiguous Memory Allocation
- Paging
- Segmentation
- Paging Combined with Segmentation
- Structure and Implementation of Page Table
- Virtual Memory in OS
- Cache Memory Organization
- Demand Paging
- Page Replacement Algorithms
- Allocation of Frames and Thrashing
- Demand Segmentation
OS Part-5
- Distributed Operating System: Introduction and Types
- Distributed OS: Design Issues
- Distributed OS: File System
- Distributed OS: Remote File Access
- Remote Procedure Call(RPC)
- Remote Method Invocation(RMI)
- Distributed Shared Memory
- Parallel Processing and Concurrent Programming
- Security and Threats Protection in Distributed OS
- Security Design Principles and Authentication in Distributed OS
- Sensor Network and Parallel OS
Operating System Overview
Operating System Kya Hai?
Ek Operating System (OS) ek tarah ka system software hai jo computer ke hardware aur software ko manage karta hai aur users ke liye ek interface provide karta hai.
Operating System ke Main Functions
-> Process Management – CPU scheduling aur process execution ka dhyan rakhta hai.
-> Memory Management – Program ke liye memory allocate aur deallocate karta hai.
-> File System Management – Data ko organize aur store karta hai.
-> Device Management – Hardware devices (printer, keyboard, etc.) ko control karta hai.
-> Security & Access Control – Unauthorized access se protection deta hai.
-> User Interface (UI) – CLI (Command Line Interface) ya GUI (Graphical User Interface) provide karta hai.
Operating System Ka Evolution
Operating Systems alag-alag computing needs ke according evolve hue hain. Neeche OS ke major types diye gaye hain jo time ke saath develop hue hain.
1. Mainframe Operating System
Time Period: 1950s – 1970s
Use Case: Bade industrial, bank, aur government systems ke liye.
Key Features:
Batch Processing support karta hai (ek saath multiple jobs process hoti hain).
Ek bada powerful computer multiple users ke liye kaam karta hai.
Input devices: Punch cards aur magnetic tapes use ki jaati thi.
Example:
IBM OS/360, UNIVAC, UNIX
Diagram:
[User] → [Terminal] → [Mainframe Computer] → [OS]
2. Desktop Operating System
Time Period: 1980s – Present
Use Case: Personal computers (PCs) ke liye.
Key Features:
Graphical User Interface (GUI) use hota hai.
Single-user ya multi-user support karta hai.
Standalone computers ke liye design kiya gaya hai.
Example:
Windows (Windows 95, XP, 10, 11)
macOS (Mac OS X)
Linux (Ubuntu, Fedora)
Diagram:
[User] → [Keyboard/Mouse] → [Personal Computer] → [OS (GUI)]
3. Multiprocessor Operating System
Time Period: 1990s – Present
Use Case: Scientific research, gaming, enterprise servers.
Key Features:
Multiple CPUs ek saath kaam karte hain.
Parallel processing se speed badhti hai.
Reliability aur fault tolerance improve hoti hai.
Example:
Linux SMP Kernel, Windows Server, IBM AIX
Diagram:
[User] → [Multiprocessor System] → [OS] → [Multiple CPUs]
4. Distributed Operating System
Time Period: 2000s – Present
Use Case: Cloud computing aur supercomputers.
Key Features:
Task ko multiple computers ke beech distribute karta hai.
Load balancing aur fault tolerance provide karta hai.
Users ko ek single system jaisa feel hota hai.
Example:
Google’s Cloud OS, Microsoft Azure, Amoeba, Sprite OS
Diagram:
[User] → [Multiple Computers in Network] → [OS (Distributed)]
5. Network Operating System (NOS)
Time Period: 1990s – Present
Use Case: File sharing, remote access aur networking.
Key Features:
Multiple computers ko ek network ke through connect karta hai.
Security aur user authentication provide karta hai.
File aur printer sharing support karta hai.
Example:
Microsoft Windows Server, Novell NetWare, UNIX/Linux Servers
Diagram:
[ User 1 ] [ User 2 ] [ User 3 ]
| | |
[Network Operating System]→[Shared Files & Resources ]
6. Clustered System
Time Period: 2000s – Present
Use Case: Supercomputing, banking, stock markets.
Key Features:
Multiple computers (nodes) ek saath kaam karte hain.
Fault tolerance aur high availability support karta hai.
Badi data processing applications ke liye useful hota hai.
Example:
IBM Cluster Systems, Google Cloud Clusters, Apache Hadoop
Diagram:
[User]→[Clustered OS]→[Multiple Servers Handling Tasks]
7. Handheld Operating System (Mobile OS)
Time Period: 2007 – Present
Use Case: Smartphones, tablets, IoT devices.
Key Features:
Touchscreen aur mobile hardware ke liye optimized hai.
Battery efficiency ko dhyan me rakha jata hai.
Apps ka ecosystem hota hai (Play Store, App Store).
Example:
Android (Linux-based), iOS (Apple), Harmony OS (Huawei)
Diagram:
[User]→[Mobile Device]→[Mobile OS (Android/iOS)]
Conclusion
Operating Systems batch processing se lekar modern AI-based systems tak evolve ho chuke hain. Har tarah ka OS alag needs ko pura karta hai:
Personal computing ke liye Desktop OS High-performance computing ke liye Multiprocessor & Clustered OS Cloud aur large networks ke liye Distributed & Network OS Mobile aur handheld devices ke liye Handheld OS