the complete guide to linux administration ch01 powerpoint

Chapter 1:Introducing Linux

The Complete Guide To Linux System Administration

The Complete Guide to Linux System Administration 2

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


Objectives (continued)

• Explore a Linux file system from the command line

• Locate additional information about commands you want to use or learn about


A Brief History

• Popular graphical computers– Apple Macintosh– Microsoft Windows

• Linux– Alternative for people whose computing needs

require something different


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


Understanding Operating Systems (continued)

• Application– Software program that provides service for

computer user– Cannot act without “permission” from

operating system


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


Operating System Functions (continued)

• Major operating system components:– Kernel– Device drivers– Shell– Utility programs– Graphical user interface (GUI)


The UNIX Operating System

• 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 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 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 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


Linux Arrives

• Linus Torvalds– 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


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


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 Strengths Of Linux

• Stability

• Security

• Speed

• Cost

• Multiprocessing and other high-end features

• Applications


Linux In The Market

• Linux is packaged and sold

• Red hat software– Current market leader


Linux Distributions

• Linux distribution– 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


Linux Distributions (continued)


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


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


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


Version Numbering

• Version numbers assigned to:– Each release of Linux kernel – Each component of Linux distribution – Linux distributions

• Most users select latest available version


Version Numbering (continued)

• Kernel version number components– Major version number– Minor version number

• Even indicates production release

• Odd indicates development release

– Patch-level number


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


Linux Certification (continued)

• Red Hat’s certification program– Very highly regarded– Training program consists of three courses


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


Careers in Linux

• System administrator

• Network administrator

• Software engineer

• Trainer

• Technical writer

• Product marketing

• Business consultant


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 Duties of a System Administrator (continued)

• Responsibilities– Keep system running smoothly– Document system– Define procedures and policies– Recover from emergencies– Plan systems


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


Starting To Use Linux

• Should have access to computer with Linux installed


Logging In

• Log in – 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


Logging In (continued)

• Modes – Graphical– Text


Graphical Environments

• Popular desktops– KDE desktop – GNOME desktop

• Features– Taskbar– Main menu– Desktop icons– Multiple overlapping windows


Opening a Terminal Window

• Terminal window– Resembles console– Enter commands from keyboard


Exploring the File System


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


File System Concepts (continued)

• Directory relationships– Parent directory– Subdirectory

• Path– List of directories– Absolute path– Relative path

• Linux does not have separate drives


File System Concepts (continued)

• Root directory– Parent of all directories– /

• /Usr subdirectory– Contains the greatest number of files and

subdirectories on newly installed systems


Managing Files With Graphical Utilities

• File manager– Nautilus– 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


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


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


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


Finding Command Help

• Learn more details

• Explore additional Linux topics


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


Linux Command Information

• Man pages– Online manual pages– Man command

• Info page– Definitive source of information– Info command


Summary

• Operating system – Provides interface between computer hardware

and applications run by user

• Linux offers important features, such as: – Stability – Speed – Security– Flexibility– Low cost


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 /


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 administration ch01 powerpoint

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