Chapter 1

Introduction to Linux

At a Glance

Class Notes Table of Contents

• Overview

• Objectives

• Teaching Tips

• Quick Quizzes

• Class Discussion Topics

• Additional Projects

• Additional Resources

• Key Terms

• Technical Notes for Hands-On Projects

Lecture Notes

Overview

Linux technical expertise is essential in today’s computer workplace as more and more companies switch to Linux to meet their computing needs. Thus, it is important to understand how Linux can be used, what benefits Linux offers to a company, and how Linux has developed and continues to develop. In the first half of this chapter, you will learn about operating system terminology and features of the Linux operating system, as well as the history and development of Linux. Later in this chapter, you will learn about the various types of Linux and situations in which Linux is used.

Chapter Objectives

In this chapter, you will learn to: • Understand the purpose of an operating system • Outline the key features of the Linux operating system • Describe the origins of the Linux operating system • Identify the characteristics of various Linux distributions and where to find them • Explain the common uses of Linux in industry today

Quick Quiz 1

1. What term is used to describe a running program on Linux? a. Application b. Process c. Runtime d. Project

2. What is represented by the second number in the Linux kernel version 2.3.4? (Choose all that apply.) a. Minor number b. Major number c. Production kernel d. Development kernel

3. Under which licensing model is Linux made available? a. GPL b. Freeware c. Shareware d. Artistic License

Quick Quiz 2

1. What Internet service provides content caching services for clients? a. DNS b. Firewall c. Proxy d. FTP

2. Which e-mail service is responsible for sending messages between services? a. MTA b. MDA c. MUA d. MHA

3. DNS can be used to map which of the following types of names to IP addresses? (Choose all that apply.) a. Hostnames b. NetBIOS names c. FQDNs d. TCP names

Class Discussion Topics

1. Have students discuss their feelings on hacker culture in general. Do they feel that it has a positive or negative impact on the world of computing? If they owned their own company, would they consider hiring someone who would describe himself or herself as a hacker? Why or why not? What impact do students think the media has in the portrayal of hackers and hacker culture?

2. Ask students which of them have worked with Linux in the past and how they felt about the experience. What were some of the challenges that they faced in attempting to install and configure Linux? Do they think that Linux will be a long-term and viable alternative to Windows and UNIX? Why or why not?

Additional Projects

1. Have students research online to find examples of different open source, closed source, freeware, and shareware applications. Have them create a table that outlines the pros and cons of each software type.

2. Have students research online to create a list of what they consider to be the best Linux resources available, along with the types of information that the sites provide. Once completed, compile the lists into a master list to be distributed to all students.

Additional Resources

1. Linux.org: http://www.linux.org

2. Linux Format Magazine: http://www.linuxformat.co.uk

3. Kernel.org: http://www.kernel.org

4. The Linux Journal: http://www.linuxjournal.com

Key Terms

• AIX A version of UNIX developed by IBM. • application The software that runs on an operating system and provides the user with specific functionality (such as word processing or financial calculation). • artistic license An open source license that allows source code to be distributed freely but changed only at the discretion of the original author. • Beowulf clustering A popular and widespread method of clustering computers together to perform useful tasks using Linux. • BSD (Berkeley Software Distribution) A version of UNIX developed out of the original o UNIX source code and given free to the University of California at Berkeley by AT&T. • closed source software The software whose source code is not freely available from the original author; Windows 7, for example. • cluster A grouping of several smaller computers that function as one large supercomputer. • clustering The act of making a cluster; see also cluster. • cracker A person who uses computer software maliciously for personal profit. • database An organized set of data. • database management system (DBMS) Software that manages databases. • developmental kernel A Linux kernel whose minor number is odd and has been recently developed yet not thoroughly tested. • device driver A piece of software containing instructions that the kernel of an operating system uses to control and interact with a specific type of computer hardware. • distribution A complete set of operating system software, including the Linux kernel, supporting function libraries and a variety of OSS packages that can be downloaded from the Internet free of charge. These OSS packages are what differentiate the various distributions of Linux. • flavor A specific type of UNIX operating system. For example, Solaris and BSD are two flavors of UNIX.

• Free Software Foundation (FSF) An organization, started by Richard Stallman, that promotes and encourages the collaboration of software developers worldwide to allow the free sharing of source code and software programs. • freeware Software distributed by the developer at no cost to the user. • frequently asked questions (FAQs) An area on a Web site where answers to commonly posed questions can be found. • fully qualified domain name (FQDN) A string of words identifying a server on the o Internet. • GNU An acronym that stands for “GNU’s not UNIX.” • GNU General Public License (GPL) A software license ensuring that the source code for any OSS will remain freely available to anyone who wants to examine, build on, or improve upon it. • GNU Network Object Model Environment (GNOME) One of the two competing graphical user interface (GUI) environments for Linux. • GNU Project A free operating system project started by Richard Stallman. • graphical user interface (GUI) The component of an operating system that provides a user-friendly interface comprising graphics or icons to represent desired tasks. Users can point and click to execute a command rather than having to know and use proper command-line syntax. • GUI environment A GUI core component such as X Windows, combined with a window manager and desktop environment that provides the look and feel of the GUI. Although functionality might be similar among GUI environments, users might prefer one environment to another due to its ease of use. • hacker A person who explores computer science to gain knowledge. It should not be confused with the term cracker. • hardware The tangible parts of a computer, such as the network boards, video card, hard disk drives, printers, and keyboards. • hardware platform A particular configuration and grouping of computer hardware, normally centered on and determined by processor type and architecture. • hot fix A solution made by a closed source vendor that fixes a software bug. • HOWTO A task-specific instruction guide to performing any of a wide variety of tasks; o freely available from the Linux Documentation Project at http://tldp.org/. • HP-UX A version of UNIX developed by Hewlett-Packard. • Internet Protocol (IP) address A unique string of numbers assigned to a computer to uniquely identify it on the Internet. • K desktop environment (KDE) One of the two competing graphical user interfaces o (GUI) available for Linux • kernel The central, core program of the operating system. The shared commonality of the kernel is what defines Linux; the differing OSS applications that can interact with the common kernel are what differentiate Linux distributions. • Linus Torvalds A Finnish graduate student who coded and created the first version of o Linux and subsequently distributed it under the GNU Public License. • Linux A software operating system originated by Linus Torvalds. The common core, or kernel, continues to evolve and be revised. Differing OSS bundled with the Linux kernel is what defines the wide variety of distributions now available.

• Linux Documentation Project (LDP) A large collection of Linux resources, information, and help files supplied free of charge and maintained by the Linux community. • Linux User Group (LUG) An open forum of Linux users who discuss and assist each other in using and modifying the Linux operating system and the OSS run on it. There are LUGs worldwide. • mail delivery agent (MDA) The service that downloads e-mail from a mail transfer agent. • mail transfer agent (MTA) An e-mail server. • mail user agent (MUA) A program that allows e-mail to be read by a user. • major number The number preceding the first dot in the number used to identify a o Linux kernel version. It is used to denote a major change or modification. • MINIX Mini-UNIX created by Andrew Tannenbaum. Instructions on how to code the kernel for this version of the UNIX operating system were publicly available. Using this as a starting point, Linus Torvalds improved this version of UNIX for the Intel platform and created the first version of Linux. • minor number The number following the first dot in the number used to identify a Linux kernel version, denoting a minor modification. If odd, it is a version under development and not yet fully tested. See also developmental kernel and production kernel. • Multiplexed Information and Computing Service (MULTICS) A prototype time- sharing operating system that was developed in the late-1960s by AT&T Bell Laboratories. • multitasking A type of operating system that has the capability to manage multiple tasks simultaneously. • multiuser A type of operating system that has the capability to provide access to multiple users simultaneously. • newsgroup An Internet protocol service accessed via an application program called a newsreader. This service allows access to postings (e-mails in a central place accessible by all newsgroup users) normally organized along specific themes. Users with questions on specific topics can post messages, which can be answered by other users. • Open Source Software (OSS) The programs distributed and licensed so that the source code making up the program is freely available to anyone who wants to examine, utilize, or improve upon it. • operating system (OS) The software used to control and directly interact with the computer hardware components. • package manager The software used to install, maintain, and remove other software programs by storing all relevant software information in a central software database on the computer. • process A program loaded into memory and running on the processor, performing a specific task. • production kernel A Linux kernel whose minor number (the number after the dot in the version number) is even and which is, therefore, deemed stable for use after widespread testing. • program A set of instructions that knows how to interact with the operating system and computer hardware to perform a specific task; stored as a file on some media (for example, a hard disk drive).

• programming language The syntax used for developing a program. Different programming languages use different syntaxes. • proxy server A server or hardware device that requests Internet resources on behalf of other computers. • Red Hat One of the most popular and prevalent distributions of Linux in North America, distributed and supported by Red Hat Inc. Fedora is a Red Hat-based Linux distribution. • revision number The number after the second dot in the version number of a Linux kernel, which identifies the certain release number of a kernel. • router A computer running routing software, or a special-function hardware device providing interconnection between networks; it contains information regarding the structure of the networks and sends information from one component network to another. • scalability The capability of computers to increase workload as the number of processors increases. • search engine An Internet Web site, such as www.google.com, where you simply enter a phrase representing your search item and receive a list of Web sites that contain relevant material. • server A computer configured to allow other computers to connect to it from across a network. • server services The services that are made available for other computers across a network. • shareware The programs developed and provided at minimal cost to the end user. These programs are initially free but require payment after a period of time or a certain amount of usage. • software The programs stored on a storage device in a computer that provide a certain function when executed. • Solaris A version of UNIX developed by Sun Microsystems from AT&T source code. • source code The sets of organized instructions on how to function and perform tasks that define or constitute a program. • SuSE One of the most popular and prevalent distributions of Linux in Europe. • system service The additional functionality provided by a program that has been incorporated into and started as part of the operating system. • tarball A compressed archive of files containing scripts that install Linux software to the correct locations on a computer system. • total cost of ownership (TCO) The full sum of all accumulated costs, over and above the simple purchase price of utilizing a product. Includes training, maintenance, additional hardware, and downtime. • UNIX The first true multitasking, multiuser operating system, developed by Ken o Thompson and Dennis Ritchie, from which Linux was originated. • user A person who uses a computer. • user interface The interface the user sees and uses to interact with the operating system and application programs. • workstation A computer used to connect to services on a server. • workstation services The services that are used to access shared resources on a network server. • X Windows The core component of the GUI in Linux.

Technical Notes for Hands-On Projects

Chapter 1 contains no hands-on projects and, as such, does not require any specific classroom setup. However, students will require access to the Internet to complete the additional exercises outlined in this file.

Chapter 2

Linux Installation and Usage

At a Glance

Class Notes Table of Contents

• Overview

• Objectives

• Teaching Tips

• Quick Quizzes

• Class Discussion Topics

• Additional Projects

• Additional Resources

• Key Terms

• Technical Notes for Hands-On Projects

Lecture Notes

Overview

This chapter explores the concepts and procedures needed to install a Fedora Linux system. The latter half of the chapter explains the various components students will use when interacting with the operating system as well as how to enter basic shell commands, obtain help, and properly shut down the Linux system.

Chapter Objectives

In this chapter, your students will learn to: • Prepare for and install Fedora Linux using good practices • Outline the structure of the Linux interface • Enter basic shell commands and find command documentation • Properly shut down the Linux operating system

Quick Quiz 1

1. What is the most common method for installing Linux? a. From an HTTP server b. From a DVD-ROM c. From packages located on the hard disk d. From an FTP server

2. What type of hard disk can have no more than four units connected to the computer at the same time? a. Serial Advanced Technology Attachment (SATA) b. Small Computer Systems Interface (SCSI) c. Parallel Advanced Technology Attachment (PATA) d. Basic Input/Output System (BIOS)

3. In which directory is the Linux kernel typically located? a. /home b. /opt c. /var d. /boot

Quick Quiz 2

1. Which keystroke combination should be used to access the tty3 terminal? a. Ctrl+Alt+F7 b. Ctrl+Alt+F3 c. Ctrl+Delete+F2 d. Ctrl+Shift+F3

2. Which command can be issued to view all users currently logged on to a server and their tasks? a. who b. w c. whoami d. id

3. Which of the following are commands associated with help on a Linux system? (Choose all that apply.) a. man b. help c. info d. whatis

Class Discussion Topics

1. Discuss some of the reasons why you either do or do not enjoy working from a traditional computer command line. Further, discuss both the advantages and disadvantages of the command line from the point of view of speed, connection types, ability to remember commands, and so forth.

2. Discuss what some of the challenges are that a company faces when it attempts to implement a very secure and stringent password policy?

Additional Projects

1. Have students use the man, info, and help pages to find the purpose of a list of common Linux commands not already covered in the text and supplied by you.

2. Have students research online to find sites that provide lists of essential commands that a new Linux system administrator should be familiar with. Compile this information into a master document to be distributed to all students.

Additional Resources

1. Linux Installation Primer: http://www.linuxgazette.com/issue32/jenkins1.html

2. Fedora Core Getting Started: http://www.johnmunsch.com/articles/FedoraCoreGettingStarted/

3. Linux Install Guide: http://www.cppsig.org/links/linux/linuxInstall.html

4. Fedora Project Homepage: http://fedora.redhat.com/

Key Terms

• Advanced Technology Attachment (ATA) See also Parallel Advanced Technology Attachment. • arguments The text that appears after a command name, does not start with a dash “-” character, and specifies information the command requires to work properly. • authentication The process whereby each user must log in with a valid user name and password before gaining access to the user interface of a system. • BASH shell The Bourne Again Shell; it is the default command-line interface in Linux. • BIOS (Basic Input/Output System) The part of a computer system that contains the programs used to initialize hardware components at boot time. • boot loader A small program started by BIOS that executes the Linux kernel in memory. • command A program that exists on the hard disk and is executed when typed on the command line. • dual booting The process of installing more than one operating system on a computer. The user can then choose the operating system to load at system startup. • ext2 A nonjournaling Linux filesystem. • ext3 A journaling Linux filesystem. • ext4 An improved version of the ext3 filesystem with an extended feature set and better performance. • extended partition A partition on a hard disk that can be further subdivided into components called logical drives.

• filesystem The way in which a hard disk partition is formatted to allow data to reside on the physical media; common Linux filesystems include ext2, ext3, ext4, REISER, and VFAT. • firstboot wizard A configuration utility that is run at system startup immediately following a Fedora Linux installation. • Free Identity, Policy, and Audit (FreeIPA) A set of security software that provides secure authentication across a network using several technologies that work together, including LDAP, Kerberos, NTP, and DNS. • GRand Unified Bootloader (GRUB) A common boot loader used in Linux. • GUID Partition Table (GPT) The area of a large hard disk (> 2TB) outside a partition that stores partition information and boot loaders. • Hardware Compatibility List (HCL) A list of hardware components that have been tested and deemed compatible with a given operating system. • info pages A set of local, easy-to-read command syntax documentation available by typing the info command. • Integrated Drive Electronics (IDE) See also Parallel Advanced Technology Attachment. • journaling A filesystem function that keeps a journal of the information that needs to be written to the hard disk; common Linux journaling filesystems include ext3, ext4, and REISER. • Lightweight Directory Access Protocol (LDAP) A protocol that is used by services to query directory databases for purposes of authentication. • logical drives The smaller partitions contained within an extended partition on a hard disk. • Logical Volume Manager (LVM) A set of services that is used to manage logical volumes stored on one or more hard disks. • man pages See manual pages. • manual pages The most common set of local command syntax documentation, available by typing the man command. Also known as man pages. • Master Boot Record (MBR) The area of a typical hard disk (< 2TB) outside a partition that stores partition information and boot loaders. • memtest86 A common RAM-checking utility. • metacharacters The key combinations that have special meaning in the Linux operating system. • Network Information Service (NIS) A set of services that is used to standardize the configuration and centralize the authentication of UNIX and Linux-based systems across a network. • Network Time Protocol (NTP) A protocol that is used to synchronize the time on a computer from across a network such as the Internet. • options The specific letters that start with a dash “-” or two and appear after the command name to alter the way the command works. • Parallel Advanced Technology Attachment (PATA) A legacy hard disk technology that uses ribbon cables to typically attach up to four hard disk devices to a single computer. • partitions A small section of an entire hard disk created to make the hard disk easier to use. Partitions can be primary or extended.

• primary partitions The separate divisions into which a hard disk can be divided (up to four are allowed per hard disk). • Redundant Array of Inexpensive Disks (RAID) A type of storage that can be used to combine hard disks together for performance and/or fault tolerance. • REISER A journaling filesystem used in Linux. • Serial Advanced Technology Attachment (SATA) A hard disk technology that allows for fast data transfer along a serial cable. It is commonly used in newer workstation and serverclass computers. • shell A user interface that accepts input from the user and passes the input to the kernel for processing. • Small Computer Systems Interface (SCSI) A high-performance hard disk technology that is commonly used in server-class computers. • swap memory See also virtual memory. • System Rescue A feature that allows you to boot a small Linux system from DVD to repair a Linux system that resides on the hard disk. • terminal The channel that allows a certain user to log in and communicate with the kernel via a user interface. • VFAT (Virtual File Allocation Table) A nonjournaling filesystem that might be used in Linux. • virtual memory An area on a hard disk, known as a swap partition, that can be used to store information that normally resides in physical memory (RAM), if the physical memory is being used excessively. • Winbind A set of software components that allows Linux computers to authenticate against a Microsoft Active Directory database.

Technical Notes for Hands-On Projects

The Chapter 2 hands-on projects require that students have access to the Fedora 15 installation DVD, a Pentium 4 class or greater computer with at least 1GB of RAM, a 60GB hard disk, and a DVD drive, as well as access to the Internet, to complete the additional exercises outlined in this instructor’s manual file.

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