Presented By B.CHANDRASEKARI, MCA., M.Phil., (C.S)

Assistant Professor Theivanai ammal College for

women,Villupuram (autonomous)

• What is Linux?• What is Kernal?– How its work?– Various type?

• What are Various types of Linux Distribution• Reference• Keywords• Thank you

• Developer:Linus Torvalds• Written in:C, assembly• OS family:Unix-like• Initial release:0.01 (17 September 1991; 23 years

ago)• Kernel type:Monolithic

• A kernel is the lowest level of easily replaceable software that interfaces with the hardware in your computer.

• It is responsible for interfacing all of your applications that are running in “user mode” down to the physical hardware, and allowing processes, known as servers, to get information from each other using inter-process communication (IPC).

–most kernels fall into one of three types: » monolithic, » microkernel, » HybriD

Linux is a monolithic kernel and Windows 7 use hybrid kernels

Microkernel

• A microkernel takes the approach of only managing what it has to: CPU, memory, and IPC. Microkernels also have a very small footprint, for both memory and install space, and they tend to be more secure because only specific processes run in user mode which doesn’t have the high permissions as supervisor mode.

Pros

Portability Small install footprint Small memory footprint Security

CONS Hardware is more abstracted

through drivers Hardware may react slower

because drivers are in user mode Processes have to wait in a queue

to get information Processes can’t get access to

other processes without waiting

Monolithic Kernel• Monolithic kernels are the opposite of

microkernels because they encompass not only the CPU, memory, and IPC, but they also include things like device drivers, file system management, and system server calls.

• Monolithic kernels tend to be better at accessing hardware and multitasking because if a program needs to get information from memory or another process running it has a more direct line to access it and doesn’t have to wait in a queue to get things done.

• This however can cause problems because the more things that run in supervisor mode, the more things that can bring down your system if one doesn’t behave properly.

Pros

More direct access to hardware for programs

Easier for processes to communicate between eachother

CONS Large install footprint Large memory footprint Less secure because everything

runs in supervisor mode

Hybrid Kernel• Hybrid kernels have the ability to pick

and choose what they want to run in user mode and what they want to run in supervisor mode.

• Often times things like device drivers and filesystem I/O will be run in user mode while IPC and server calls will be kept in the supervisor mode.

Pros

Developer can pick and choose what runs in user mode and what runs in supervisor mode

Smaller install footprint than monolithic kernel

More flexible than other models

CONS

Can suffer from same process lag as microkernel

Device drivers need to be managed by user (typically)

•All the other pieces you find in a Linux distribution - the Bash shell, the KDE window manager, web browsers, the X server, Tux Racer and everything else - are just applications that happen to run on Linux and are emphatically not part of the operating system itself.•The kernel makes its services available to the application programs that run on it through a large collection of entry points, known technically as system calls.

The Linux kernel is a Unix-like computer operating system kernel.

The Linux kernel, developed by contributors worldwide, is a prominent example of free and open source software.

The kernel is a piece of software that, roughly speaking, provides a layer between the hardware and the application programs running on a computer. In a strict, computer-science sense, the term 'Linux' refers only to the kernel - the bit that Linus Torvalds wrote in the early 90s.

• Red Hat: One of the earliest players in the game, Red Hat now position itself strongly in the business market. It has created a community-supported distribution, Fedora Core, which is the choice of many for desktop use.

• Debian: The most popular community-created distribution. Debian is an excellent choice for server environments. Debian has also been used as the base for many specialist distributions.

• Ubuntu: Desktop usability, out of the box. Taglined "Linux for human beings,” Based on Debian.

• SUSE: Novell's answer to Red Hat, comes in “enterprise” and a community-based OpenSUSE

• All Distributions have their respective strengths.

• Debian-based– 1.1 Knoppix-based– 1.2 Ubuntu-based

• 1.2.1 Official distributions• 1.2.2 Old official distributions• 1.2.3 Third-party distributions

• Gentoo-based(frequently updated software and highly optimized)• Pacman-based (Package manager that is capable of resolving dependencies)

– 3.1 Arch-based• RPM-based (Red hat Linux and Suse Linux use RPM file format)

– 4.1 Fedora-based• 4.1.1 RHEL-based

– 4.2 Mandriva Linux-based– 4.3 openSUSE-based

• Slackware-based(highly constamizeable distribution)– 5.1 Slax-based

• Independent

• Focuses on usability.• Offered by Dell on many of their products• Offers Firefox, Openoffice, Games• Variations of Ubuntu:– Edubuntu, a distribution designed for classrooms using

GNOME – Kubuntu, a desktop distribution using KDE rather than

GNOME – Xubuntu, a "lightweight" distribution based on the Xfce

desktop environment instead of GNOME – Mythbuntu, a distribution that is tied heavily to MythTV – Ubuntu Studio, a multimedia-creation flavor of Ubuntu

• Owned by Novell, Inc.• Several desktop environments such as KDE

and GNOME and window managers like Window Maker and Blackbox are included

• Some multimedia features• Openoffice.org and Realplayer• Designed for Business/commercial use and

networking

• RH Enterprise Linux (RHEL) is targeted toward the commercial market, including mainframes.

• Includes software for database management:– Linux 2.6.18 – Apache 2.2.3 – MySQL 5.0.22 – PHP 5.1.6 – PostgreSQL 8.1.4 – GNOME 2.16 – KDE 3.5.4

•

• Specialization for Power Architecture processors (IBM Power, PowerPC, Cell) Multicore processor

• Supports accelerated graphics and audio hardware out-of-the-box.

• Includes:– Firefox– Openoffice– Instant Messaging– Media Players

• Is the first supported alternative OS for Sony’s Playstation 3 (Cell)

• Wikipedia http://en.wikipedia.org/wiki/List_of_Linux_distributions

http://en.wikipedia.org/wiki/SUSE_Linux http://en.wikipedia.org/wiki/Red_Hat_Linux http://en.wikipedia.org/wiki/Ubuntu_%28Linux_distribution%29 http://en.wikipedia.org/wiki/Yellow_Dog_Linux

• DistroWatch http://distrowatch.com/

• GNU is an operating system that is free software

• GPL is an General Public License• GNOME is led by the non-profit GNOME

Foundation• KDE is a powerful graphical desktop

environment for Unix workstations