A glance into Operating Systems and File Systems

Atif Ahmed

Overview

An operating system (OS) is an interface between a computer user and computer hardware.

Under Operating System's "umbrella"

An operating system (OS) is system software that manages computer hardware and software resources and provides common services for computer programs.

It performs all the basic tasks like:

Memory management
Process management
Controlling peripheral devices
File management

Memory management

An Operating System does the following activities for memory management:

Keeps tracks of primary memory, i.e., what part of it are in use by whom, what part are not in use.
Allocates the memory when a process requests it to do so.
De-allocates the memory when a process no longer needs it or has been terminated.

Process management

An Operating System does the following activities for process management:

Keeps tracks of processor and status of process.
Allocates the processor (CPU) to a process.
De-allocates processor when a process is no longer required.
Decides which process gets the processor when and for how much time. This function is called process scheduling.

Controlling peripheral devices

An Operating System does the following activities for controlling peripheral devices (device management):

Keeps tracks of all devices.
Decides which process gets the device when and for how much time.
Allocates the device in the efficient way.
De-allocates devices.

File management

An Operating System does the following activities for file management:

Keeps track of information, location, uses, status etc. The collective facilities are often known as file system.
Decides who gets the resources.
Allocates the resources.
De-allocates the resources.

File System

File control block

Architecture (1)

Architecture (2)

Hardware layer - Hardware consists of all peripheral devices (RAM/ HDD/ CPU etc).
Kernel - It is the core component of Operating System, interacts directly with hardware, provides low level services to upper layer components.
Shell - An interface to kernel, hiding complexity of kernel's functions from users. The shell takes commands from the user and executes kernel's functions.
Utilities - Utility programs that provide the user most of the functionalities of an operating systems.

References

Operating System - Wikipedia
https://en.wikipedia.org/wiki/Operating_system
Operating System quick guide
https://www.tutorialspoint.com/operating_system/os_quick_guide.htm
Operating System Users List
http://www.technologydatagroup.com/techlists/operating-system-users-list/

Thank You

http://atif93.github.io/os-tutorial-basic/