Chapter 1: Introducing Linux The Complete Guide To Linux System Administration

Objectives Describe how Linux was created and how it compares to other operating systems List versions of Linux currently available Outline the skills required and challenges facing a system administrator Log in and begin using a Linux system The Complete Guide to Linux System Administration

Objectives (continued) Explore a Linux file system from the command line Locate additional information about commands you want to use or learn about The Complete Guide to Linux System Administration

A Brief History Popular graphical computers Linux Apple Macintosh Microsoft Windows Linux Alternative for people whose computing needs require something different The Complete Guide to Linux System Administration

Understanding Operating Systems Software Collection of instructions that control the tasks a computer performs Can be changed without disassembling the computer and rewiring Operating system Software that helps other programs control computer hardware and interact with users The Complete Guide to Linux System Administration

Understanding Operating Systems (continued) Application Software program that provides service for computer user Cannot act without “permission” from operating system The Complete Guide to Linux System Administration

Operating System Functions Initialize computer hardware Allocate system resources to programs Keep track of multiple programs running at same time Provide organized method for all programs to use system devices The Complete Guide to Linux System Administration

Operating System Functions (continued) Major operating system components: Kernel Device drivers Shell Utility programs Graphical user interface (GUI) The Complete Guide to Linux System Administration

The UNIX Operating System Originally created at AT&T Bell Labs in early 1970s Designed to control networked computers that were shared by many users Features and low cost of Linux effectively driving UNIX out of market The Complete Guide to Linux System Administration

The Free Software Foundation and the GNU Project Free software foundation (FSF) Software itself should not be restricted in distribution by standard commercial license agreement GNU project Completely free version of UNIX Written from scratch The Complete Guide to Linux System Administration

The Free Software Foundation and the GNU Project (continued) Software license Legal definition of who can use software and how it can be used GNU general public license (GPL) Very different from standard commercial software license Author agrees to give away source code Anyone is licensed to redistribute it in any form The Complete Guide to Linux System Administration

The Free Software Foundation and the GNU Project (continued) GNU GPL Any modifications to the source code must be licensed under the GPL Sometimes called copyleft OpenSource Refers to software licensed under GPL Public domain No one has copyright to software Not same as GPL The Complete Guide to Linux System Administration

Linux Arrives Linus Torvalds Linux development method Decided to create UNIX-like operating system kernel for IBM-compatible PC Solicited help via Internet Released Linux kernel under GPL Linux development method Person identifies need and begins writing program Developer announces project on Internet The Complete Guide to Linux System Administration

Linux Arrives (continued) Linux development method (continued) Others respond and work on different parts of project Person leading project releases software People download source code and try program; send back information about problems Developers fix bugs Forking Creating new project based on existing source code The Complete Guide to Linux System Administration

Motivating Free Software Developers Why would so many people devote so much effort to something without expecting any reward? Fills developer’s specific technical need Respect of like-minded professionals Sense of contribution and community Valuable boost to developer’s resume The Complete Guide to Linux System Administration

The Strengths Of Linux Stability Security Speed Cost Multiprocessing and other high-end features Applications The Complete Guide to Linux System Administration

Linux In The Market Linux is packaged and sold Red hat software Current market leader The Complete Guide to Linux System Administration

Linux Distributions Linux distribution System utilities Price Productized version of Linux Includes operating system kernel along with other components System utilities Related to managing Linux system Price Generally between $2 and $100 The Complete Guide to Linux System Administration

Linux Distributions (continued) The Complete Guide to Linux System Administration

Red Hat Software Fedora distribution Free product Red Hat Enterprise Linux configurations WS (workstation) ES (enterprise server) AS (application server) Red Hat Enterprise Linux Sold as subscription service The Complete Guide to Linux System Administration

Red Hat Software (continued) Red Hat Enterprise Linux Updates from Red Hat Network (RHN) Red Hat Excels in service and support offered to large companies using Linux The Complete Guide to Linux System Administration

Hardware Requirements Can run on very minimal hardware Recommend that computer have minimum of: 1 GB of free disk space 64 MB of RAM For Red Hat Enterprise Linux installations: 256 MB of RAM 300 MHZ CPU 800 MB of free disk space The Complete Guide to Linux System Administration

Version Numbering Version numbers assigned to: Each release of Linux kernel Each component of Linux distribution Linux distributions Most users select latest available version The Complete Guide to Linux System Administration

Version Numbering (continued) Kernel version number components Major version number Minor version number Even indicates production release Odd indicates development release Patch-level number The Complete Guide to Linux System Administration

Linux Certification Industry certification programs Red Hat Certified Technician Red Hat Certified Engineer LPI Certification Linux Certified Administrator (LCA) Certification Linux+ Certification Novell Certified Linux Engineer The Complete Guide to Linux System Administration

Linux Certification (continued) Red Hat’s certification program Very highly regarded Training program consists of three courses The Complete Guide to Linux System Administration

The Work of a System Administrator Linux is increasingly part of information technology infrastructure of large organizations Knowledge of Linux can set you on path to a fulfilling and profitable career The Complete Guide to Linux System Administration

Careers in Linux System administrator Network administrator Software engineer Trainer Technical writer Product marketing Business consultant The Complete Guide to Linux System Administration

The Duties of a System Administrator Role Make technology work and continue to work for those who do “real work” of organization Enable others to use technology benefits Responsibilities Create new user accounts Maintain system hardware Train end users The Complete Guide to Linux System Administration

The Duties of a System Administrator (continued) Responsibilities Keep system running smoothly Document system Define procedures and policies Recover from emergencies Plan systems The Complete Guide to Linux System Administration

Ethics, Privacy, and the Law Working as system administrator involves many ethical issues Fellow employees count on your work to do theirs Best route to success comes through making employer successful System administrators guild (SAGE) www.sage.org The Complete Guide to Linux System Administration

Starting To Use Linux Should have access to computer with Linux installed The Complete Guide to Linux System Administration

Logging In Log in User account Identify yourself to operating system so that it knows: You are authorized to use system Which parts of system to permit you to access User account Set of permissions to use system Has associated user name and password The Complete Guide to Linux System Administration

Logging In (continued) Modes Graphical Text The Complete Guide to Linux System Administration

Graphical Environments Popular desktops KDE desktop GNOME desktop Features Taskbar Main menu Desktop icons Multiple overlapping windows The Complete Guide to Linux System Administration

Opening a Terminal Window Resembles console Enter commands from keyboard The Complete Guide to Linux System Administration

Exploring the File System The Complete Guide to Linux System Administration

File System Concepts Files are organized into directories Names are case sensitive Names can be long Names may contain many different types of characters Can include file extensions Not required The Complete Guide to Linux System Administration

File System Concepts (continued) Directory relationships Parent directory Subdirectory Path List of directories Absolute path Relative path Linux does not have separate drives The Complete Guide to Linux System Administration

File System Concepts (continued) Root directory Parent of all directories / /Usr subdirectory Contains the greatest number of files and subdirectories on newly installed systems The Complete Guide to Linux System Administration

Managing Files With Graphical Utilities File manager Displays contents of a directory as collection of icons or file names Manage files and directories Choose Browse Filesystem on main menu Home directory Subdirectory where all personal files are stored The Complete Guide to Linux System Administration

Working at a Command Line Linux system administrators should be very comfortable working at command line Much faster way to perform most tasks Some tasks cannot be use graphical interface Commands pwd  mv  slocate cd  ls  file mkdir  cat  cp rmdir  touch The Complete Guide to Linux System Administration

Working at a Command Line (continued) Command-line prompt consists of: User name Name of computer at which you are working Last directory name in current working directory $ character The Complete Guide to Linux System Administration

Working at a Command Line (continued) Parameters Define what command will operate on Options Alter how command operates Timestamp Information about date and time when event occurred The Complete Guide to Linux System Administration

Finding Command Help Learn more details Explore additional Linux topics The Complete Guide to Linux System Administration

Reading Linux Documentation Linux documentation project (LDP) HOWTOS Linux on the internet www.google.com Documentation included with software packages Software packages provide some documentation /Usr/doc /Usr/share/doc The Complete Guide to Linux System Administration

Linux Command Information Man pages Online manual pages Man command Info page Definitive source of information Info command The Complete Guide to Linux System Administration

Summary Operating system Linux offers important features, such as: Provides interface between computer hardware and applications run by user Linux offers important features, such as: Stability Speed Security Flexibility Low cost The Complete Guide to Linux System Administration

Summary (continued) Several Linux certification programs are available Several versions of Red Hat Enterprise Linux Most users rely on GUI to log in and use Linux Text-only mode also available Information in Linux is stored in directories Begins with root directory / The Complete Guide to Linux System Administration

Summary (continued) Linux files can include file extensions Few Linux programs rely on file extensions to define what file contains Information about Linux is available online Part of LDP The Complete Guide to Linux System Administration