An operating system (OS) is a software that manages hardware resources and provides services for computer programs. It is the most fundamental system software that is responsible for managing the overall functionality of a computer system. An OS plays a crucial role in facilitating communication between the user, computer hardware, and applications. It provides an environment where users can interact with the computer and run applications.
User Services:
An operating system provides several services to users to help them interact with the computer. These services include:
User Interface:
The OS provides a user interface (UI) that allows users to interact with the computer through a graphical user interface (GUI) or a command-line interface (CLI). The UI provides various tools and applications that users can use to manage their files, applications, and settings.
File Management:
The OS provides a file management system that allows users to create, delete, copy, move, and organize files and directories on the computer’s storage devices.
Security:
The OS provides security features to protect user data and system resources from unauthorized access. It includes user authentication, access control, and data encryption.
Printing:
The OS provides printing services that allow users to print documents on printers connected to the computer.
Multimedia Support:
The OS provides multimedia support for audio and video playback, as well as support for image viewing and editing.
Process Management:
An operating system manages processes, which are instances of programs that are currently running on the computer. The OS provides several services to manage processes efficiently. These services include:
Process Scheduling:
The OS schedules processes to run on the CPU in a way that optimizes system resources and ensures fairness.
Process Synchronization:
The OS provides mechanisms to allow processes to synchronize their activities and avoid conflicts.
Memory Management:
The OS manages memory allocation and deallocation for processes and ensures that each process has access to the memory it needs.
Input/Output Management:
The OS manages input/output (I/O) operations for processes and ensures that I/O requests are handled efficiently.
Error Handling:
The OS provides error handling services to detect and recover from errors that may occur during process execution.
System Services:
An operating system provides several services to other system components and applications. These services include:
Device Drivers:
The OS provides device drivers that allow applications to communicate with hardware devices such as printers, scanners, and network adapters.
Networking:
The OS provides networking services that allow applications to communicate over the network and access remote resources.
Virtualization:
The OS provides virtualization services that allow multiple operating systems to run on the same physical hardware.
Security:
The OS provides security services to protect the system from viruses, malware, and other security threats.
Resource allocation: The OS manages system resources such as CPU, memory, and I/O devices and allocates them to processes and applications as needed.
OS-2022
Q-1.
(a) Write are the functions of operating systems? write a note on multi programmed operating systems ?
(b) Distinguish between client server and peer to peer model of distributed systems .
Q-2.
(b) What is meant by Storage Structure? Discuss Storage Hierarchy.
Q-3.
(a) What are the criteria for evaluating the CPU scheduling algorithms? Why do we need it?
Q-4.
(a) What is synchronization? Explain how semaphores can be used to deal with n-process critical problem.
Q-5.
Q-6.
(b) What are the disadvantages of single contiguous memory allocation? Explain.
Q-7.
(a) Briefly explain about single-level, two-level and three Structured directories.
(b) What is disk scheduling? Explain the C-SCAN scheduling by giving an example.
Q-8.
(b) UNIX file system.
(c) Program and system threats.