1. My Lecture Notes:
Have a tutorial value: the student should be able to learn from slides,
Comply with research-based principles for design Power Point presentation
Concepts are presented visually with many diagrams and pictures.
They use visual aids (diagrams, pictures etc.) and pictures are presented near each other on the page or screen.
The context is presented in the hierarchical way, details are indented
Important key words are highlighted or written in different color

2. Overview of Operating Systems
Chapter 1-2
Overview of Operating Systems
UNIX/LINUX History
Credits: Parts of the slides are based on slides created by textbook authors,
Syed M. Sarwar, Robert Koretsky, Syed A. Sarwar
expanded by Jozef Goetz, 2014

3. Objectives To explain what an operating system is
To describe briefly operating system services
To describe character and graphical user interfaces – GUI
To discuss different types of operating systems
To briefly describe the LINUX operating system
To describe briefly the history of the LINUX operating system
To provide an overview of the different types of LINUX systems

4. What is an Operating System?
Primary purpose is to facilitate:
Easy, efficient, fair, orderly and secure use of hardware and software resources.
Allows users to employ
application software,
language libraries, system calls and
program generation tools.
Two ways of viewing an operating system:
Top-down – user view
E.g., The OS performs the task of dealing with complicated hardware resources and gives you a comprehensive and simple machine, ready to use.
In this way the OS provides a virtual machine
Bottom up – system view
E.g., the OS decides how much space how much RAM space is to be allocated to a program before it is loaded and executed
In this was the OS can be viewed as a resource manager.

5. Layered View of a Computer System
App.
User’s
Interface
App.
Programmer's
Interface

6. Operating System Services
Communication between processes
Process control
Create, terminate processes
Allocate and free memory
Execution of a program
Input and output operations performed by programs
Device management
Manipulation of all types of files
File management
Management of users and security
Error detection and reporting

7. Character Versus Graphical User Interface.
Character (Command Line) User Interface – CUI or CLI
Input device (e.g., Keyboard is used to issue a command)
Efficient
A minimal layer of software is needed between you and your task on computer

8. Character Versus Graphical User Interface.
Graphical User Interface - GUI
Input is taken from a point-and-click device.
Most popular desktop environments:
GNU (pronounced /ˈɡnuː/) is a Unix-like computer operating system developed by the GNU project, ultimately aiming to be a "complete Unix-compatible software system“ composed wholly of free software.
The licenses for most software and other practical works are designed to take away your freedom to share and change the works.
By contrast, the GNU General Public License is intended to guarantee your freedom to share and change all versions of a program--to make sure it remains free software for all its users.
GNU was founded by Richard Stallman
GNU - A set of programs written by the Free Software Foundation to provide a Free UNIX framework.
GNU is a large component of a Linux distribution.
Variants of the GNU operating system, which use the kernel called Linux, are now widely used;
though these systems are often referred to as “Linux”, they are more accurately called GNU/Linux systems.
GNU Network Object Model Environment – GNOME
K Desktop Environment - KDE

9. Types of Operating Systems
Single-user, single-process system (e.g. DOS)
Single-user, multiprocess system
Multiuser, multiprocess system
The CPU can be moved from one process to another process - multiprogramming
multiprocess system increases resource utilization and system throughput
Time-sharing systems - Multiuser, multiprocess and interactive operating system OS
The CPU is switched from one process to another giving the impression of sole use of the system

10. The Development of the UNIX Operating System
Research Operating System
UNIX Version 1 through UNIX Version 6
Developed and Written in C
Releases distributed as C Source Code
The design of the system allowed users to run multiple processes concurrently and to connect these processes with streams.
AT& T System V
Released in 1983
Berkley Software Distributions
3BSD and 4BSD
The History of Shells
Bourne Shell,
C Shell,
Korn Shell.
Current and Future Developments - UNIX

12. What is Linux?
Linux is a clone of the operating system Unix, written from scratch by Linus Torvalds ’91 with assistance from a loosely-knit team of hackers across the Net.

13. Table 2.1 Web Resources (continued on next slide)

14. Table 2.1 Web Resources (continued from previous slide)

15. Table 2.2 Major LINUX Distributions
Top Ten Distributions most widely-used by Linux users around the world as of 11/5/14: - #2 Ubuntu
Ubuntu, Linux Mint and PCLinuxOS are considered the easiest for new users who want to get productive in Linux as soon as possible without having to master all its complexities.
On the other end of the spectrum, Slackware Linux, Arch Linux and FreeBSD are more advanced distributions that require plenty of learning before they can be used effectively. 
openSUSE, Fedora, Debian GNU/Linux and Mageia can be classified as good "middle-road" distributions.
CentOS is an enterprise distribution, suitable for those who prefer stability, reliability and long-term support over cutting-edge features and software.
Android is a quite different GUI placed on top of GNU/Linux designed specifically for smart-thingies. One of the the best OS for smart-thingies because of the huge number of applications you can get for it.

16. The 5 most popular Linux distributions as of 11/5/14
From the bottom up we find and :
5: Fedora: But while Debian isn't one of my favorites, I confess I really haven't cared for Fedora, Red Hat's community Linux distribution, in recent years. Well, it's not so much Fedora, it's the fact that it uses GNOME 3.x -- the desktop interface I love to hate.
Regardless of how I feel about it though, Fedora clearly has its fans. And, if you work on Red Hat Enterprise Linux (RHEL) development, it's a really wise idea to keep a copy of Fedora on hand so you can see RHEL's future.
4: Mageia: And, number two is, "who?" I can hear some of you asking. Mageia is a September 2010 fork of Mandriva Linux, a commercial Linux distribution, which was once quite popular in its own right. In 2006, Mandriva suffered management and financial problems. Since then, while the firm has continued to have problems, Mageia -- freed of Mandrivia's business woes -- has continued on to become a wildly popular Linux distribution.
And why is Mageia so popular? I think it's because it's a straightforward easy-to-use Linux distribution. Unlike Ubuntu's Unity user interface, Mageia uses the Linux pro friendly KDE 4.8 desktop. In short, it's just a darn good KDE distribution -- which, by the way -- according to LinuxQuestions' last survey, is now the single most popular desktop interface of all.
3: Debian: I've never been a big Debian fan -- I much prefer Debian-based distributions such as Ubuntu and Mepis -- but lots of other people are. Debian, which just turned 19, remains important not just because it is the foundation for many other Linux distributions, but because year after year it continues to be loved by its users.
2 Ubuntu: What's that you say? Ubuntu: the darling of so many Linux fans only in third place? Yep. It's in third. Why? Well even though I like its relatively new Unity interface, a lot of other people really don't. I think that mostly it's because while Unity is great for new users who aren't especially computer savvy, a lot of Linux professionals find it gets in the way -- and, of course, experienced old Linux hands are exactly the kind of people who visit DistroWatch.
That said, Ubuntu founder Mark Shuttleworth thinks the operating system will see 20 million new PCs sold with Ubuntu in 2012, and that's not counting people who install it. Those people will also largely be new computer users. If Ubuntu can get most of the new users coming to Linux, I think they'll be happy even if they're no longer as popular with old-guard Linux desktop users.
1: Mint Linux: This should come as no surprise. Mint is an excellent distribution and my own personal favorite. Users have enjoyed and loved using it ever since Ubuntu started down the Unity path.
What Mint has going for it is an outstanding desktop interface of its own, Cinnamon, which is very remindful of the classic GNOME 2.x interface. Add to that outstanding software and hardware support, there's little question as to why Mint still appears to be the most desktop popular Linux of all.

17. Distribution of Linux
If you're new to Linux, you don't want to download the kernel - a component in a working Linux system.
Instead, you want what is called a distribution of Linux, which is a complete Linux system there are over 250 varieties of LINUX
There are numerous distributions available for download on the Internet as well as for purchase from various vendors
some are general-purpose, and some are optimized for specific uses.
mirrors of several distributions available at mirrors.kernel.org
To install Linux visit

18. Linux growth IBM is the Linux market leader
- Linux related articles
- Apache’s projects Web site
- GNU website
IBM is the Linux market leader
- 30% share vs. HP at 26% and vs. Dell at 15%
Took market share from both HP and Dell in Linux x86 revenue in 2004 (surpassing Dell for the first time)
!!!
- OS market share

19. Linux growth
Linux in 2005
New 2.6 kernel addresses both scalability and linear performance issues
Linux 3.1 (stable) as of 10/23/ what’s new
Linux stable kernels , , and as of 14 Sep 2012
Here are usually several "longterm maintenance" kernel releases provided for the purposes of backporting bugfixes for older kernel trees.
Longterm release kernels:
Version Maintainer Released Projected EOL
Greg Kroah-Hartman Aug, 2016
Jiri Slaby
Greg Kroah-Hartman Sep, 2015
3.4 Li Zefan Sep, 2016
Ben Hutchings
Willy Tarreau Mid-2015

20. Linux growth Reliability remains outstanding
Note: reliability is highly dependent on systems manufacturer
Availability/failover extensions can now be readily found
failover - the transfer of operation from a failed component (e.g., controller, disk drive) to a similar, redundant component to ensure uninterrupted data flow and operability
LINUX can be received:
- From Linux suppliers such as Red Hat, Novell (SuSE), or other United Linux suppliers
From traditional hardware/software vendors such as Oracle, IBM and HP
HP offers open source and Linux solutions for the largest enterprises to small and medium businesses.
- From point product failover software makers
- From grid suppliers (in the form of distributed resource management software)

21. Linux growth
Linux is, today, a solid enterprise-class environment with a rich infrastructure ecosystem
Needs improvement in packaged applications support
value Linux over Windows in terms of
security,
low cost, and
reliability.”
Red Hat Enterprise Linux is the leading platform for open source computing.
It is sold by subscription, delivers continuous value and is certified by top enterprise hardware and software vendors.
From the desktop to the datacenter, Enterprise Linux couples the innovation of open source technology and the stability of a true enterprise-class platform.
The Fedora Project ( ) is a Red Hat sponsored and community-supported open source project with the goal of working with the Linux community to build a complete, general purpose OS exclusively from free software.

22. Linux growth
UNIX and Linux System Administration Handbook, 4e (Nemeth et al ISBN ) has long been hailed as the all-in-one reference for UNIX and Linux system administration.
The book goes beyond the "what" and "how" to explain the "why" of system administration. This edition adds extensive new coverage reflecting the realities of today's IT environments, and anticipates tomorrow's.
The book has been thoroughly updated to cover today's leading Linux and Unix platforms, including modern versions of Red Hat Enterprise Linux, openSUSE, and Ubuntu; Solaris and OpenSolaris 11; HP-UX 11i v3, and even AIX 6.1.

23. LINUX http://en.wikipedia.org/wiki/Linux:
It is a leading operating system on servers and other big iron systems such as mainframe computers and supercomputers:more than 90% of today's 500 fastest supercomputers run some variant of Linux, including the 10 fastest.