January 17th, 2011

Submitted to: Mr. Faisal Shehzad Submitted by: Bilal Haider, Mehreen Nawaz, Sadaf Afzal, Samia Akhtar, Nukhba Afzal, Anila Yasin, Sabiha Reyaz [ MCS 2010-12 – SEMESTER 1 - MORNING]

Department of Computer Science – The Islamia University of Bahawalpur

WINDOWS

V/S LINUX A COMPARATIVE STUDY

WINDOWS V/S LINUX: A COMPARATIVE STUDY 2011

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In the name of Allah the Most Merciful and the Most Beneficent

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Contents

The need of a comparative study ……………………………….1

Overview ……………………………………………………….1

License ………………………………………………….…1

Cost …………………………….………………………….2

Market Share And Usage ……………………………………3

Distributions/ Flavors ………………………………………3

General Differences …………………………..…………………4

User Interfaces ………………………………………………4

Command line Interface …………………………………4

Graphical user Interface …………………………………5

Usability ……………………………..………………………6

Stability ………………………………..…………………….6

Security ………………………………..…………………….6

Applications/ Softwares ……………………………………...7

Multi-user Environments ……………..…….……………….7

Technical Differences …………………………………………….8

Hardware Support ………………..………………………….8

Structure ………………………….………………………….8

Windows ……………………..………………………….8

Linux …………………………………………………….9

Networks …………………………………………………….9

Performance …………….………………………………….10

Virtualization ………………………………………………11

References …………………………………………………….12

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TTHHEE NNEEEEDD OOFF AA CCOOMMPPAARRAATTIIVVEE SSTTUUDDYY The study of the differences between operating systems usually helps

students in developing a deep understanding regarding implementation of

the various structures and algorithms to fulfill specific requirements for an

operating system. The comparison is also required when we have to

decide which operating system should be adopted in an environment

particularly a large environment where a wrong decision could cause

delay in its operations or a huge monetary loss. Furthermore, these studies

help in evaluating the system performance.

This document illustrates some major differences between Microsoft

Windows and Linux. As the number of distributions of Linux is huge, some

common features of “GNU/Linux” will be discussed alongwith Linux Kernel

version 2.6.37, being the latest version. Similarly, different versions of

Windows are present to cater different purposes, here will be discussed the

Windows NT 6.1, which serves as a base for the latest, Windows 7 and

Windows Server 2008 R2.

OOVVEERRVVIIEEWW

LLIICCEENNSSEE Linux is an open source operating system

making available its source code online and most of

its distributions come with the GNU General Public

License (GPL) and GNU Lesser General Public

License (LGPL), allowing the users to modify and

redistribute the system under the same license.

Contrarily, Microsoft Windows is a closed source, and

to some extent a shared source operating system, so

only some of the source code is provided when some

eligibility criteria is met. Windows comes with a

Microsoft End User License Agreement (MS-EULA)

which prohibits the installation of a single OS on

several machines (One Copy per Computer).

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CCOOSSTT

The acquisition costs for Windows are generally much higher than

Linux. Microsoft allows a single copy of Windows on only one computer. In

contrast, Linux is completely free and you can run it on any number of

computers. However, the hidden cost in Linux lies in its support and

maintenance, but this typically does not affect home users. But businesses

are required to get subscription based support from other companies.

Similarly, Linux systems require relatively higher paid administrators which

increase the Total Cost of Ownership (TCO) of Linux.

However, the TCO of Linux is generally perceived as much lower

than that of Windows. The chief technology architect at Merrill Lynch & Co.

is quoted in Computer World for stating that “the cost of running Linux is

typically a tenth of the cost of Unix and Microsoft alternatives”. On the

other side Microsoft claimed in 2004 that "Linux was found to be over 10

times more expensive than Windows Server 2003" but got warned from UK's

Advertising Standards Authority (ASA) which regarded it as misleading.

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MMAARRKKEETT SSHHAARREE && UUSSAAGGEE

When we see at the general market share analysis of both operating

systems, Windows certainly dominates but these analyses are formed by

the web access counts. In addition, usage of both operating systems varies

greatly. Windows is generally preferred for desktops, but Linux is highly

preferred for Servers, Supercomputers and Embedded systems. Linux is also

gaining popularity in smartphones.

DDIISSTTRRIIBBUUTTIIOONNSS// FFLLAAVVOORRSS

Microsoft Windows family has two main operating systems intended

for personal computers and servers, namely Windows 7 and Windows

Server 2008 R2, which have further editions classified according to the

features and functionality provided. Similar is the case with Linux, as Linux is

only a kernel, not always but most operating systems come as GNU/Linux.

These Linux derivatives are called distributions. Major distributions are Red

Hat, Debian, Ubuntu, Fedora, SuSE for computers and Android, Maemo,

MeeGo for smartphones. These distributions vary drastically as these are

designed for different uses and targeted at different user groups.

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GENERAL DIFFERENCES

UUSSEERR IINNTTEERRFFAACCEESS

Command Line Interface

The Command Interpreter in Linux is called Shell. While the most

common is GNU Bash, more than one shell can also be used on a Linux

system. As these are much powerful, the CLI on Linux is preferred for

administrative tasks. CLI is always accessible as the user has option to load

the CLI before GUI (Multilayered Run Levels). Whereas the Command

Interpreter called “Command Prompt” in Windows is not that powerful and

does not provide any benefit over the GUI.

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Graphical User Interface

In Linux, the GUI is not considered the part of Linux Kernel, so the

distributions have to implement some other solution. Commonly used GUIs

are „GNOME‟, „KDE‟, and „Xfce‟ and most famous user interfaces operate

on top of the „X Window System‟. In some cases the GUI may not be

implemented, like in embedded systems and servers, where the tasks are

performed using CLI. The GUI in Windows is considered the part of the

operating system. „Windows Shell‟ GUI is used in Windows systems with

„Desktop Window Manager‟. The Server operating system, like Linux, can

be operated without the GUI.

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UUSSAABBIILLIITTYY Usability depends heavily on the focus of that operating system;

Windows‟ focus is on consistency, usability and safety while Linux focuses

more on performance, customizability and safety. Although the majority

Linux variants have improved dramatically in ease of use, Windows is still

much easier to use for new computer users. A “user friendly” software

means software that can be used to a reasonable level of competence by

a user with no previous experience of the software i.e. learning curve. As

far as the user friendliness of Windows and Linux operating system is

concerned, Windows appear to be more user friendly then Linux operating

system. However, Linux has some plus points over Windows like many

distributions provide “Live CD” installation which allows the user to use the

operating system before it is actually installed.

SSTTAABBIILLIITTYY The majorities of Linux variants are notoriously reliable and can often

run for months and years without needing to be rebooted. Linux supports

multiple copies of the Kernel on the system such that if an error is

encountered and the Kernel becomes corrupted, a different copy of the

Kernel can be used to boot up the system, through the GRUB boot loader.

As the device drivers can cause serious stability issues, Windows is providing

“WHQL Testing”, which ensures the compatibility of third party driver with

the operating system. Linux, most of the time has drivers included in its

kernel, others are usually developed by the community, minimizing the

stability issues. Downtime for Linux is minimum; in circumstance no

hardware reset is needed.

SSEECCUURRIITTYY Linux, being an open source operating system, has always been

considered very secure as compared to Windows, as open source offers a

faster and more effective response to bugs and viruses. Similarly, open

source operating system has millions of eyes on it, so the possible threats

are constantly detected and removed. In addition, users perform their

tasks as Limited Accounts, where permission for every system task is

required and no user access to registry is provided. Whereas Windows is

generally perceived as more vulnerable to security threats, its closed

source nature allows only a team of limited developers fix the threats and

usually the updates are released once in a month. The user privileges are

implemented in Windows by using “User Account Control” Framework.

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AAPPPPLLIICCAATTIIOONNSS// SSOOFFTTWWAARREESS Linux has a large variety of available software programs, utilities, and

games. However, Windows has a much larger selection of available

software. Many of the available software on Linux are open source hence

available at low cost or free. Every type of software is available for

Windows as Windows is regarded as a general purpose operating system.

However, Linux is less common for general use and this has effects on the

development trends, so the entertainment applications like multimedia,

games etc are rarely available for Linux. But, there are softwares available

for Linux, like WINE, which add a compatibility layer under Windows

applications to run on Linux.

MMUULLTTII--UUSSEERR EENNVVIIRROONNMMEENNTTSS Linux is a true multi-user operating system, designed to handle

thousands of users at a time. While Windows can support hundreds or

thousands of networked users, but the operating system isn't true multi-user

operating system. The system administrator is the only "user" for Windows.

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TECHNICAL DIFFERENCES

HHaarrddwwaarree SSuuppppoorrtt The most interesting aspect of Linux, given its size and complexity, is

its portability. Linux can be compiled to run on a huge number of

processors and platforms with different architectural constraints and needs.

While the Windows operating system can run on various available

architectures, it does not have that level of versatility.

SSttrruuccttuurree

Windows

Windows has hybrid kernel i.e. microkernel implemented like a

monolithic kernel. Some of the subsystems run in user space and some in

kernel space. The Windows architecture consists of two modes; user mode

and kernel mode. Further, user mode comprises two subsystems, the

Environment subsystem, which runs different applications, and the Integral

subsystem, which operates system specific functions on behalf of the

environment subsystem.

Similarly, kernel mode has

executive services, kernel

drivers, a kernel and

a Hardware Abstraction

Layer (HAL). Executive

services subsystem is made

up of many modules, that

perform specific tasks, like I/O

Manager, IPC Manager, VM

Manager, Process Manager,

Power Manager Etc. While

the kernel performs almost all

the tasks of a traditional

microkernel, kernel mode

drivers are used to

communicate with hardware

devices at kernel level, so all

the user mode

applications/services see the

hardware as file objects.

Hardware Abstraction Layer provides a consistent platform for kernel to run

on, by hiding differences in underlying hardware.

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Linux

Linux has monolithic kernel with modules, means Linux is a dynamic

kernel, supporting the addition and removal of software components,

called dynamically loadable kernel modules which can be inserted at

boot when they're needed. Linux architecture has two layers. At the top is

the user space where the user applications are executed. Below the user

space is the kernel space. Here, the Linux kernel exists. There is also the

GNU C Library which connects the system call interface to the kernel. The

Linux kernel space can be divided into three levels. At the top is the system

call interface and below

this is the kernel code,

which can be more

accurately defined as the

architecture-independent

kernel code, which include

the subsystems for Process

Management, Memory

Management, File Systems,

Networks and Device

Drivers. This code is

common to all of the

processor architectures

supported by Linux. Below

this is the architecture-

dependent code, which

serves as the processor

and platform-specific

code for the given

architecture.

NNEETTWWOORRKKSS Linux, being a production operating system and open source, is a

great test bed for new protocols and advancements of those protocols.

Linux supports a large number of networking protocols, including the

typical TCP/IP, and also extension for high-speed networking (greater than

1 Gigabit Ethernet [GbE] and 10 GbE). Linux also supports protocols such as

the Stream Control Transmission Protocol (SCTP), which provides many

advanced features above TCP (as a replacement transport level

protocol).

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PPEERRFFOORRMMAANNCCEE Linux is generally considered faster as compared to Windows. As the

Linux distributions range from minimal operating systems to full-fledged,

very powerful systems, Ubuntu is selected for performance comparison with

Windows 7. Here are given the results of some of benchmark tests.

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VVIIRRTTUUAALLIIZZAATTIIOONN A recent advancement of Linux is its use as an operating system for

other operating systems (called a hypervisor). Recently, a modification to

the kernel was made called the Kernel-based Virtual Machine (KVM). This

modification enabled a new interface to user space that allows other

operating systems to run above the KVM-enabled kernel. In addition to

running another instance of Linux, Microsoft® Windows® can also be

virtualized. The only constraint is that the underlying processor must support

the new virtualization instructions.

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RReeffeerreenncceess:: 1. Linux vs. Windows.

http://computerhope.com/issues/ch000575.htm

2. 10 fundamental differences between Linux and Windows

http://blogs.techrepublic.Com.com/10things/?p=406

3. Linux vs. Windows

http://www.michaelhorowitz.com/Linux.Vs.Windows.html

4. kernel Comparison Linux vs Windows

http://widefox.pbworks.com/w/page/8042308/Kernel-Comparison-Linux-vs-

Windows

5. The Linux Kernel Archives: Linux Kernel Organization, Inc.

http://kernel.org

6. Anatomy of Linux Kernel

http://www.ibm.com/developerworks/linux/library/l-linux-kernel/

7. Linux Architecture

http://en.wikipedia.org/wiki/Linux_architecture

8. Architecture of Windows NT

http://en.wikipedia.org/wiki/Architecture_of_Windows_NT

9. Microsoft's Linux ad 'misleading'.

http://news.bbc.co.uk/1/hi/technology/3600724.stm

10. Linux vs Windows TCO Comparison.

http://www.cyber.com.au/about/linux_vs_windows_tco_comparison.pdf

11. Operating System Market Share (10-01-2011)

http://www.netmarketshare.com/operating-system-market-

share.aspx?qprid=8&qpcal=1&qp stick=1

12. Web Server Survey

https://secure1.securityspace.com/s_survey/data/201007/index.html

13. Operating system Family share for 11/2010

http://top500.org/stats/list/36/osfam

14. Linux Operating Systems

http://www.altiusdirectory.com/Computers/linux-operating-systems.html

15. Benchmarked: Ubuntu vs Vista vs Windows 7

http://www.tuxradar.com/node/33

16. Linux vs. Windows Hardware Support: The Truth

http://www.tannerhelland.com/371/linux-windows-hardware-support/