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Chapter One Summary Overview IT120 Network Operating Systems
Chapter 1 Operating System Fundamentals
In this chapter, the student gains an understanding of operating systems (OS)
including Windows and UNIX. The first personal computers (PCs) were designed as
stand-alone desktop systems. The development of Network Operating Systems (NOS)
enabled multiple users to share resources and files. Security became necessary to
protect systems from inside and outside threats.
1.1 Operating System Basics
1.1.1 Overview of PC operating systems
Desktop microcomputers started to gain popularity in the 1980s. They were
stand-alone systems that could not communicate with each other or the
powerful mainframes.
Discuss how the limited productivity started the evolution of networks.
1.1.2 PCs and computer networks
As desktop computing matured in the workplace, companies installed Local
Area Networks (LANs) to connect desktop PCs. This enabled the PCs to
share data and peripherals, such as printers.
How were LANs created?
Discuss how networking has evolved.
1.1.3 The Kernel
Kernel is the most common term for the core of the operating system. The
kernel is a relatively small piece of code that is loaded into memory when
the computer boots. This computer code contains instructions that allow
the kernel to manage hardware devices, such as disk drives. The kernel
also manages and controls memory allocation, system processes, and
other programs. Application software and other parts of the operating
system rely on the kernel to provide basic scheduling services and access
to the computer's hardware and peripherals.
What would happen if the kernel became corrupted?
1.1.4 The user interface
The User Interface (UI), is the most visible part of a computer's operating
system. The UI is the component that facilitates communication between
the user and the operating system. It acts like a bridge between the user
and the kernel. The UI is like an interpreter, translating user keystrokes,
mouse clicks, or other input for the appropriate programs.
What is a shell?
User interfaces fall into two general categories:
•
Command-Line Interface (CLI)
A CLI environment is completely text-based and the user
must input commands with the keyboard.
• Graphical User Interface (GUI)
Today, all popular desktop operating systems support GUIs. A
GUI allows the user to manipulate software using visual objects such as
Instructor: Jack D. Locher
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Chapter One Summary Overview IT120 Network Operating Systems
windows, pull down menus, pointers, and icons. The GUI allows the user
to input commands using a mouse or another point-and-click device.
Why do end users prefer using a GUI?
What is the tradeoff for simplifying the UI?
1.1.5 The file system
The file system of an OS determines more than just how files and folders are logically
organized. The type of file system determines:
•
•
Whether or not files can be secured from other users or programs
How data is physically arranged on the storage media, such as a hard drive
Some file systems use disk space more efficiently than others.
One common type of file system is called File Allocation Table (FAT). FAT file systems
are maintained on the disk by the operating system.
Provide a visual of the table and show how the files are stored. What does
the table contain?
A given file may be stored on several clusters, but a cluster can contain data from
only one file.
There are three types of FAT file systems. They are FAT16, FAT32, and NTFS.
FAT16 was created for use on larger partitions of up to 4 GB. Although larger disks can
be formatted in FAT16, to do so is an inefficient use of disk space. In FAT, larger
partitions result in larger cluster sizes.
For example, with a 512 MB partition the size of the clusters (the basic storage units) is
8 KB. This means that a 1 KB file uses 8 KB of space, because more than one file
cannot be stored in a cluster. The extra 7 KB is wasted.
FAT32 was developed to overcome the problem of wasted space. This 32bit file
system uses smaller cluster sizes on large disks. It supports partitions up to 2
terabytes (TB) in size.
Figure
in the on-line curriculum 1.1.5, shows which file systems are used by the
various operating systems.
Note: There are some operating systems that will accommodate more
than one type of file system.
The file system determines file naming conventions and the format for specifying a
path, or route, to the file's location.
The student should be able to identify the rules for naming files. What are
illegal characters in filenames?
1.1.6 Common desktop operating systems
Over the past twenty years, desktop operating systems have evolved to include
sophisticated GUIs and powerful networking components. Because networking
and the Internet have become such an integral part of using a computer, the
desktop operating system is rapidly converging with the network operating
system.
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Chapter One Summary Overview IT120 Network Operating Systems
The student should be able to list the different operating systems used
today.
Worksheet 1.1.6 Operating System Basics
Please note that in this worksheet (and in Lab and Worksheet Solutions),
question 8, the last item in the table should read “IBM OS/4” not “Linux”.
Please also note that Ext4 is one of the supported file systems for IBM OS/4.
1.2 Microsoft Windows
1.2.1 MS-DOS
MS-DOS began as a simple operating system with a text-based CLI. MSDOS was designed to run on the 16 bit, 8 bit data bus, Intel 8088 processor.
MS-DOS was a 16 bit operating system, which could handle processing only
16 bits (2 bytes) at one time.
MS-DOS and 16 bit processing are obsolete in today's Internet-based and
graphically oriented desktop environment. The standard for modern operating
systems is 32 bit, and a handful of 64 bit operating systems are available for
systems that have 64 bit processors.
Discuss the advantages and disadvantages of MS-DOS.
1.2.2 Microsoft Windows 3.1
Running MS-DOS with Windows 3.x addresses many of the shortcomings of
MS-DOS. The Windows 3.x shell provides a GUI and supports cooperative
multitasking, which enables users to run more than one program
simultaneously.
Cooperative multitasking is not the best way to implement multitasking.
Why?
Networking with Windows 3.1
MS-DOS and Windows 3.1 require that additional network client software is
installed in order to connect to a network. Windows for Workgroups 3.1, which
was released in 1992, was the first Microsoft operating system to have
networking components built-in. Microsoft released Windows for Workgroups
3.11 in 1993.
1.2.3 Windows 9x
Windows 9X includes Windows 95a, 95b, 98, 98SE, and ME.
A more efficient form of multitasking first used in Windows 9x is called
Preemptive Multitasking, which is also used in newer versions of Windows. The
operating system controls the allocation of processor time, and 32 bit programs
run in their own separate address spaces.
With preemptive multitasking, an unruly program cannot take over the system. If
one program crashes it does not affect the others.
How does time slicing work in preemptive multitasking?
Networking with Windows 9x
The Windows 9x operating systems include networking client software. Client
software allows the OS to participate in server-based networks. Clients take
advantages of services that are offered by systems running NOS software, such as
Instructor: Jack D. Locher
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Chapter One Summary Overview IT120 Network Operating Systems
Windows NT or Novell Netware. These services include authentication, file sharing,
printer sharing, directory/naming services, mail service, and web services.
What is backward compatibility?
1.2.4 Windows NT and Windows 2000
Windows NT runs on an entirely new kernel. Windows NT does not rely on the old
DOS related code that other versions of Windows had been built on. The Windows NT
software featured improved file security, stability, networking, and 32 bit support. Since
that time, Windows NT supported a new file system called NTFS.
Explain the differences between FAT and NTFS.
The NT 5.0 project was eventually named "Windows 2000" after the year in which it was
finally released. Despite Microsoft's original intention to release a home user version of
the software, Windows 2000 has remained an OS for power users, corporate desktops,
and high-end servers.
1.2.5 Windows XP
Windows XP was released in 2001 and represents the first OS built on NT that was
directly targeted toward home, as well as corporate, desktops. The Windows XP family
includes:
.
.
.
•
•
•
Windows XP – Targeted for home users
Windows XP Pro – Targeted for power users and corporate desktops
Windows .NET server – Targeted for servers as a NOS
Discuss the differences in XP, XP Pro, and .NET server.
1.2.6 Windows GUI
The Windows GUI is perhaps the most recognizable user interface in the world.
The Windows 9x, NT, 2000, and XP operating systems all share common elements in
their GUIs.
The student should be able to navigate and list all components of the desktop.
1.2.7 Windows CLI
All Windows operating systems include a command line environment that enables the
user to enter common MS-DOS commands.
How is the command line accessed?
Note: In Windows NT, 2000, and XP, enter cmd instead of command to
access DOS.
1.2.8 Windows Control Panel
The Windows Control Panel is a central location for making system
configuration changes.
What are the different ways to navigate to the control panel.
The student should be able to list the key tasks that can be accomplished
using the control panel.
Worksheet 1.2.8 Microsoft Windows Basics
Instructor: Jack D. Locher
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Chapter One Summary Overview IT120 Network Operating Systems
1.3 UNIX and Linux on the Desktop
1.3.1 Origins of UNIX
UNIX is the name of a group of operating systems that trace their origins back
to 1969 at Bell Labs. Since its inception, UNIX was designed to support
multiple users and multitasking. UNIX was also one of the first operating
systems to include support for Internet networking protocols. The history of
UNIX, which now spans over 30 years, is complicated because many
companies and organizations have contributed to its development.
The student should be able to list some of the different releases of UNIX.
1.3.2 Origins of Linux
In 1991, a Finnish student named Linus Torvalds began work on an
operating system for an Intel 80386-based computer.
Search the Internet for Torvalds. Torvald's homepage is not what would be
expected. The unofficial homepage of FAQ is interesting as are the interviews
with LInus Torvalds.
By the late 1990s, Linux had become a viable alternative to UNIX on
servers and Windows on the desktop. Versions of Linux can now run on
almost any 32 bit processor, including the Intel 80386, Motorola 68000,
Alpha, and PowerPC chips.
The student should be able to list some of the more popular releases of
Linux.
Linux is one of the most powerful and reliable operating systems in the world
today. Because of this, Linux has already made an impact as a platform for
power users and in the server industry. Linux is not often deployed as a
corporate desktop operating system. Although GUI interfaces are available to
make Linux user friendly, most beginning users find Linux more difficult to use
than MacOS or Windows.
Why is application support a consideration when Linux is implemented on a
desktop system?
Networking with Linux
Recent distributions of Linux have networking components built-in for
connecting to a LAN, establishing a dialup connection to the Internet, or
other remote network. In fact, TCP/IP is integrated into the Linux kernel
instead of being implemented as a separate subsystem.
Discuss the advantages and disadvantages of Linux.
1.3.3 UNIX/Linux GUI
Both UNIX and Linux are capable of running GUIs. Since there are so many
different versions of both UNIX and Linux, there are literally dozens of popular
graphical interfaces to choose from.
UNIX and Linux both rely on the X Window System to display the GUI. The X
Window System is software that works with the system's hardware and
graphical applications including the "window manager".
Discuss GNOME and KDE.
Instructor: Jack D. Locher
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Chapter One Summary Overview IT120 Network Operating Systems
1.3.4 UNIX/Linux CLI
UNIX and Linux were designed to be extremely flexible and customizable.
UNIX and Linux support dozens of user interfaces. The most common are the
text-based interfaces called Shells.
UNIX and Linux shells are somewhat difficult to learn because they rely on
abbreviations and complex command syntax. However, most Network
Administrators consider the CLI to be faster.
The student should be able to list the different shells used by UNIX and
Linux.
What determines the shells that are available to users for PCs running
UNIX or Linux?
1.3.5 Linux and UNIX system configuration tools
The various versions of UNIX and Linux offer a variety of configuration tools
similar to Windows Control Panel. Some of these tools are text-based, for
CLI environments. Some of these tools, such as linuxconf for Linux or
admintool for Solaris, can be used in a GUI.
The student should understand configuration utilities and the key tasks that can
be performed.
Worksheet 1.3.5 UNIX and Linux on the Desktop
1.4 Network Operating System Overview
1.4.1 Common network operating systems
In contrast to early desktop PC software, NOSs provide built-in networking
components and network services, multiuser capability, and sophisticated file
security and file sharing technologies.
What is meant by a robust kernel?
Why would a NOS not have a GUI?
What does the file system for a NOS require?
1.4.2 Windows and Linux NOS Comparison
In the past, the Windows and Linux operating systems offered customers and
end users a clear choice and comparison. Recently, the comparison of
Windows and Linux has become not so distinct anymore. Linux has made
strong gains in promoting its viability in the market as a competitor and
alternative to Windows.
How has the marketing strategy of Linux changed recently in order to
compete with Microsoft?
Compare some of the similarities and differences in terms of Cost,
Obtaining the Operating System, Ablity to Run from a CD, Available
Application Software, and Obtaining Application Software.
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Chapter One Summary Overview IT120 Network Operating Systems
1.4.3 The client-server model
Most network applications, including Internet related applications such
as the World Wide Web and e-mail, are built around a client/server
relationship.
What is the function of the server?
In theory, any computer can act as a server as long as it is connected to
the network and is configured with the appropriate software.
However, most organizations put all of their key network services on high
end computers called servers running NOSs optimized for servicing remote
clients.
What is a typical client/server configuration?
1.4.4 Evaluating customer resources and requirements
One of the first things that must be taken into consideration when buying or
building a new computer are the requirements that are needed to allow the
system to efficiently provide the service. Determining the customer
resources will also help decide on what type of system to build or buy for
the customer.
Most computers that are sold are not designed to have Linux run on them.
Therefore, evaluating certain requirements such as hardware and software
will help in every other step in configuring Linux for the system.
What are the requirements for a Linux workstation?
What are the requirements for a Linux server?
What is a dedicated appliance?
What factors should be considered when evaluating customer resources?
Chapter 1 Summary
This chapter covered the fundamentals of the PC. Some of the important concepts to retain from
this chapter include the following:
.
•
The NOS provides built-in networking components and network services,
multiuser capability, and sophisticated file security and file sharing technologies.
.
•
Kernel is the most common term for the core of the operating system. This
computer code contains instructions that manage hardware devices, such as disk drives. The
kernel also manages and controls memory allocation, system processes, and other programs.
•
The UI acts like a bridge between the user and the kernel. The UI is the
interpreter. The UI translates user keystrokes, mouse clicks, or other input for the appropriate
programs. Program output can be organized and displayed by the UI. On a UNIX or Linux
system, a UI is typically called a Shell. User Interfaces fall into the two general categories of CLI
and GUI.
.
•
The file system of an OS determines whether or not files can be secured from
other users or programs. The file system also defines how data is physically arranged on the
storage media, such as a hard drive. One common file system is called a FAT.
.
•
The Internet is built around a set of rules or protocols collectively known as
TCP/IP. The majority of network services and client programs use TCP/IP to exchange data.
Instructor: Jack D. Locher
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Chapter One Summary Overview IT120 Network Operating Systems
The next chapter is an introduction to networking. The student will learn the types of networks,
the importance of the OSI model, and network protocols.
Chapter 1 Notes
Instructor: Jack D. Locher
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