JNTU B.Tech III OPERATING SYSTEMS Previous Question Paper (September - 2021 - R16)

An operating system acts as an intermediary between the computer user and the computer hardware. Its primary functions include:

• Process Management: Creating, deleting, suspending, and resuming processes, and providing mechanisms for process synchronization and communication.
• Memory Management: Tracking which parts of memory are currently in use, deciding which processes to load into memory, and allocating/deallocating memory space.
• File Management: Managing files and directories, including creating, deleting, and manipulating files, as well as mapping files onto secondary storage.
• I/O System Management: Managing the buffer-caching system, providing general device-driver interfaces, and controlling specific hardware devices.
• Secondary Storage Management: Managing free space, allocating storage, and scheduling disk access.
• Protection and Security: Controlling access to system resources and ensuring that only authorized users can access files or execute processes.
• Command Interpreter System: Providing an interface for users to issue commands to the operating system.

Computing environments have evolved to meet diverse user needs. Key environments include:

• Personal Computing: Systems designed for single-user interaction, such as PCs and laptops, focusing on ease of use and responsiveness.
• Time-Sharing/Multiprogramming: Environments where multiple users share a single CPU, allowing concurrent execution of tasks to maximize resource utilization.
• Distributed Systems: A collection of physically separate, heterogeneous computer systems networked together to appear as a single system to the user, providing increased reliability and resource sharing.
• Client-Server Systems: A model where client machines request services (like database access) from a central server, which processes and returns the results.
• Cloud Computing: An extension of distributed systems that delivers computing services—including servers, storage, and databases—over the internet on a pay-per-use basis.
• Real-Time Systems: Specialized systems where processing must occur within strict time constraints, often used in industrial control or medical equipment.
• Embedded Systems: Computing systems integrated into larger devices (e.g., washing machines, automobiles) with limited resources and specific, dedicated tasks.