Chapter 1
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tanushaChapter 1
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tanushaOperating system -
Introduction
Week 1
Praveen Kumar K
Sr.Gr.Lecturer,
Dept. of CSE
Govt. Polytechnic, Mosale Hosahalli.
Operating System
Operating system is the interface between users
and computer hardware.
INTERFACE
Operating System Architecture - Unix
MS Office,
Adobe, Games
Types of Operating Systems
Operating System Modes
1. User mode – execute user programs
2. Kernel Mode – execute system programs
Kernel Vs Microkernel In OS
• Size and scope:
• Kernel: Monolithic kernels are large and include operating system functions
within the kernel itself.
• Microkernel: Microkernels are small and only include the fundamental
functions such as process communication, memory management, and basic
scheduling.
• Modularity:
• Kernel: Monolithic kernels are less modular
• Microkernel: Microkernels are modular
• Performance:
• Kernel: Monolithic kernels have better performance
• Microkernel: Microkernels have slightly lower performance
• Examples:
• Kernel: Linux, Windows, UNIX.
• Microkernel: Mach microkernel.
Functions of Operating Systems
• Process Management:
• Creation, scheduling, and termination of processes.
• Allocating resources and managing the execution of multiple processes concurrently.
• Memory Management:
• Allocating and deallocating memory for processes.
• Handling virtual memory and memory paging.
• File System Management:
• Creation, deletion, and manipulation of files.
• Managing directories and file organization.
• Device Management:
• Managing input and output (I/O) devices such as printers, keyboards, and storage
devices.
• Device drivers for communication with hardware.
• Security and Access Control:
• User authentication and authorization.
Contd..
• User Interface:
• Providing a user interface for interaction with the system.
• Supporting graphical user interfaces (GUIs) or command-line interfaces (CLIs).
• Network Management:
• Facilitating communication over networks.
• Managing network connections, protocols, and resources.
• Error Handling:
• Detecting and reporting hardware and software errors.
• Implementing error recovery mechanisms.
• System Calls:
• Providing an interface for applications to request services from the operating
system.
• Resource Allocation:
• Allocating resources like CPU time, memory, and I/O devices to processes.
• Balancing resource usage to optimize system performance.
Corporate/Business Needs Personal/Consumer Needs
Resource Management User-Friendly Interface
Security and Access Control Multimedia Support
Networking Internet Browsing and
Communication
Enterprise Applications Device Compatibility
Backup and Recovery Energy Efficiency
Five common types of operating system installations
• Clean Installation (Fresh Installation):
• A clean installation involves installing the operating system on a computer or device
that does not have any previous version of the same OS.
• This method typically wipes out all existing data on the storage device, providing a
fresh start with the new OS.
• Upgrade Installation:
• An upgrade installation is performed when a new version of the operating system is
installed over an existing older version.
• Dual Boot Installation:
• In a dual-boot setup, two or more operating systems are installed on the same
computer, and users can choose which OS to run during the boot process.
• Network Installation (Network Boot or Remote Installation):
• Network installations involve installing the operating system over a network rather
than from local media like a DVD or USB.
• Unattended Installation:
• Unattended installations are automated setups where the OS installation process
runs without requiring constant user input.
Boot methods
• Cold Boot
A cold boot refers to the process of starting a computer from a powered-off or
completely shut-down state.
• Warm Boot
A warm boot, also known as a soft boot or restart, involves restarting a
computer without turning off the power.
• Network Boot
Network booting allows a computer to start up and load its operating system
from a network server rather than from a local storage device.
• Boot from USB/External Drive:
This method involves booting a computer from an external USB drive or
another removable storage device rather than the internal hard drive.
• Dual Boot
Dual booting allows a computer to have two or more operating systems
installed, and the user can choose which OS to boot into during the startup
process.
File System
• A file system is a method used by operating systems to organize and store data on
storage devices, such as hard drives, SSDs, USB drives, and optical discs.
• It provides a hierarchical structure for organizing files and directories.
• Each file system has its own set of rules and metadata to manage file storage,
retrieval, and manipulation.
• Ex:
• FAT (File Allocation Table)
• Features: Simple structure, compatibility with various operating systems
• NTFS (New Technology File System)
• Features: Advanced features like file permissions and encryption
• exFAT (Extended File Allocation Table)
• Features: Designed for flash drives, supports large files and volumes.
• HFS+ (Hierarchical File System Plus)
• Features: Used in macOS
• EXT4 (Fourth Extended File System)
• Features: Used in Linux systems, supports large file sizes and volumes.
• F2FS (Flash-Friendly File System)
• Features: Optimized for flash-based storage devices like SSDs and eMMC(embedded MultiMediaCard).
Formatting
• Formatting is the process of preparing a storage device for data
storage by creating a file system on it.
• There are two main types of formatting:
• Quick Format:
• Description: Only initializes the file system structures, doesn't check for bad
sectors.
• Advantage: Faster but may not identify underlying disk issues.
• Full Format:
• Description: Checks for bad sectors and marks them, ensuring a more
thorough verification.
• Advantage: Ensures a more reliable disk surface.
Post installation tasks
• After installing an operating system, there are several post-installation
tasks that you may need to perform to ensure your system is properly
configured, secure, and ready for use.
• Update the System
• Driver Installation
• User Account Setup
• Network Configuration
• Firewall Configuration
• Antivirus Software
• Backup Configuration