IT241 Operating System
Operating System notes
10 chapter notes, in syllabus order. Each starts with the key points.
Unit 1
OS Basics: Functions, Services, Types & EvolutionUnit 1 of Operating System covers the core concepts of operating systems, including their definitions, functions, services, types, and historical evolution, with real-world applications and exam-focused insights.8 min readUnit 2
Processes & Threads: Definitions, States, Hierarchies & MultithreadingUnit 2 of Operating System: Covers process vs. thread definitions, lifecycle states, creation/deletion, inter-process communication (IPC), thread models (user/kernel), and real-world applications in banking, e-commerce, and mobile apps with visual comparisons and exam-focused examples.10 min readUnit 3
CPU Scheduling: Algorithms, Metrics & Real-World ImpactUnit 3 of Operating System explores how CPU scheduling algorithms allocate processor time to processes, covering key metrics (turnaround time, waiting time), scheduling classes (preemptive vs non-preemptive), and real-world applications in banking, e-commerce, and mobile apps. This note includes visual comparisons of F9 min readUnit 4
Process Synchronization: Race Conditions, Critical Sections & Synchronization ToolsUnit 4 of Operating System explores how concurrent processes coordinate access to shared resources to avoid race conditions, starvation, and deadlocks, covering critical sections, synchronization primitives (mutexes, semaphores, monitors), and real-world applications in banking, e-commerce, and traffic management.8 min readUnit 5
Deadlocks: Conditions, Prevention, Avoidance, Detection & RecoveryUnit 5 of Operating System explores deadlocks in detail—what they are, the four necessary conditions (mutual exclusion, hold-and-wait, no preemption, circular wait), prevention and avoidance strategies, detection algorithms, and recovery techniques. Includes real-world examples from banking, e-commerce, and traffic sys8 min readUnit 6
Memory Management: Allocation, Swapping, Paging, Segmentation & Virtual MemoryUnit 6 of Operating System: Covers how OS manages primary and secondary memory, including allocation strategies (contiguous, paging, segmentation), swapping, memory protection, and virtual memory techniques (demand paging, page replacement algorithms) with real-world examples from Nepalese apps and hardware.14 min readUnit 7
Virtual Memory: Paging, Segmentation, Demand Paging & ThrashingUnit 7 of Operating System: Explores virtual memory concepts—how systems use paging, segmentation, and demand paging to manage memory efficiently, prevent thrashing, and optimize performance with real-world examples from Nepalese apps and hardware.17 min readUnit 8
File Systems: Structure, Operations, and ManagementUnit 8 of Operating System explores file systems, covering their types, structures, operations, and management techniques, including file allocation methods, directory structures, and performance optimization strategies.18 min readUnit 9
I/O Systems, Disk Scheduling & Storage ManagementUnit 9 of Operating System: Covers I/O subsystems (hardware/software layers), buffering/caching, disk scheduling algorithms (FCFS, SSTF, SCAN, C-SCAN, LOOK), RAID levels, and storage management (partitioning, formatting, booting). Includes real-world examples from eSewa, NTC, and Daraz.8 min readUnit 10
OS Security, Protection & Linux Case StudyUnit 10 of Operating System explores protection mechanisms (access control, capabilities), security threats (viruses, DoS), Linux security features (SELinux, AppArmor), and a hands-on case study of Linux’s security architecture—covering real-world attacks, defenses, and configuration.10 min read