MCA(S5)20 KRISHNA KANTA HANDIQUI STATE OPEN UNIVERSITY Housefed Complex, Dispur, Guwahati - 781 006 Master of Computer Applications LINUX SYSTEM ADMINISTRATION CONTENTS UNIT- 1 : Introduction to Linux UNIT- 2 : Linux Basics UNIT- 3 : Linux Shell Script UNIT- 4 : System Administration UNIT- 5 : Linux Networking Subject Expert Prof. Anjana Kakati Mahanta, Deptt. of Computer Science, Gauhati University Prof. Jatindra Kr. Deka, Deptt. of Computer Science and Engineering, Indian Institute of Technology, Guwahati Prof. Diganta Goswami, Deptt. of Computer Science and Engineering, Indian Institute of Technology, Guwahati Course Coordinator Tapashi Kashyap Das, Assistant Professor, Computer Science, KKHSOU Arabinda Saikia, Assistant Professor, Computer Science, KKHSOU SLM Preparation Team Units Contributor 1 , 2 Pritam Medhi Research Scholar, Deptt. of Computer Science, Gauhati University 3, 4, 5 Nanu Alan Kachari Scientific Officer, Deptt. of Computer Science and Engineering, Indian Institute of Technology Guwahati July 2013 © Krishna Kanta Handiqui State Open University No part of this publication which is material protected by this copyright notice may be produced or transmitted or utilized or stored in any form or by any means now known or hereinafter invented, electronic, digital or mechanical, including photocopying, scanning, recording or by any information storage or retrieval system, without prior written permission from the KKHSOU. Printed and published by Registrar on behalf of the Krishna Kanta Handiqui State Open University. The university acknowledges with thanks the financial support pro- vided by the Distance Education Council, New Delhi, for the preparation of this study material. Housefed Complex, Dispur, Guwahati- 781006; Web: www.kkhsou.net COURSE INTRODUCTION This is a course on “Linux System Administration”. This course contains five essential units. Unit 1 is an introductory unit on Linux operating system. With this unit, the learners will be acquainted with some important concepts like open source, free software, various Linux distribution, basic architecture of Linux etc. This unit also discusses various installation process of Linux operating system. Unit 2 discusses the basics of Linux. This includes the login process, process of creating user account and group, operation with files, and some important Linux commands. The most widely used shell script is introduced in Unit 3. Unit 4 concentrates on System Administration. Unit 5 is the last unit and it discusses Linux Networking. The learners will learn how to install and configure a simple LAN. This unit also discusses installation and congiguration of proxy server, web server, file server, Samba server, SSH server etc. While going through a unit, you will notice some boxes along-side, which have been included to help you know some of the difficult, unseen terms. Some “ACTIVITY’ (s) have been included to help you apply your own thoughts. Again, we have included some relevant concepts in “LET US KNOW” along with the text. And, at the end of each section, you will get “CHECK YOUR PROGRESS” questions. These have been designed to self-check your progress of study. It will be better if you solve the given problems in these boxes immediately, after you finish reading the section in which these questions occur and then match your answers with “ANSWERS TO CHECK YOUR PROGRESS” given at the end of each unit. MASTER OF COMPUTER APPLICATIONS Linux System Administration DETAILED SYLLABUS Unit 1: Introduction to Linux Basic idea on Proprietary, Open Source, Free Software etc., Introduction of Various Linux Distribution (Red Hat Enterprise Linux, Cent OS, Fedora Projects, Debian Linux, Ubuntu, etc.); Basic Architecture of Unix/Linux system, Kernel, Shell. Linux File System, Boot block, Super block, Inode table, Data blocks, How Linux access files, storage files, Linux standard directories, LILO, GRUB Boot Loader; Installation of Linux system- Using Live CD, Virtual Machine, Direct Installation; Partitioning the Hard drive for Linux, init and run levels; Unit 2: Linux Basics Getting Started: Login process, Creating Users Account and Group, Getting Help. Services and Process, Files and File System (File Types and Permissions, Links, Size and Space, Date and Time) Working with Files: Reading Files, Searching for files, Copying, Moving, Renaming, Deleting, Linking, and Editing Files; Other Commands: ls, rm, rmdir, pwd, more ,less. grep, awt, sort, cat, head, tail, wc, tee, ps, top, tar, unzip, nice, kill, netstat, Disk related commands, checking disk free spaces. Unit 3: Linux Shell Script Various types of Shell available in Linux, Comparisons between various Shells, Shell programming in bash, read command, conditional and looping statements, case statements, parameter passing and arguments, Shell variables, system shell variables, shell keywords, creating Shell programs for performing various tasks. Unit 4: System Administration System Administration Common administrative tasks, identifying administrative files – configuration and log files, Role of system administrator, Managing user accounts-adding & deleting users, changing permissions and ownerships, Creating and managing groups, modifying group attributes, Temporary disable user’s accounts, creating and mounting file system, checking and monitoring system performance file security & Permissions, becoming super user using su; Getting system information with uname, host name, disk partitions & sizes, users, kernel. Backup and restore files, reconfiguration hardware with kudzu, installing and removing packages in Linux. Configure X-windows starting & using X desktop. KDE & Gnome graphical interfaces, changing X windows settings. Unit 5: Linux Networking Installation and configuration of a simple LAN; Installation and configuration of: Proxy server(Squid), DNS server(BIND), Mail server, Web server(Apache), File server(Samba), DHCP server; Installation and configuration of a SSH server and cliant; Installation and configuration of FTP server and cliant; Introduction to Linux Unit 1 UNIT - 1: INTRODUCTION TO LINUX UNIT STRUCTURE 1.1 Learning Objectives 1.2 Introduction 1.3 Proprietary, Open Source, and Free Software 1.4 Linux distributions 1.5 Linux/Unix system architecture – Kernel, Shell 1.6 Linux file system 1.7 Linux standard directories 1.8 Installing the Linux system 1.9 Hard drive partitioning for Linux – init and run levels 1.10 Let Us Sum Up 1.11 Answers To Check Your Progress 1.12 Further Readings 1.13 Model Questions 1.1 LEARNING OBJECTIVES After going through this unit, you will be able to: know the basics of the linux operating system know the different distribution of linux study the architecture of the linux operating system know the linux file system learn about the linux system installation study partitioning for the linux system 1.2 INTRODUCTION Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of Linux is the Linux kernel, an operating system kernel first released on 5 October 1991, by Linus Torvalds. Since the C compiler that builds Linux and the main supporting user space system tools and libraries originated in the GNU Project, initiated in 1983 by Richard Stallman, the Free Software Foundation prefers the name GNU/Linux. 1 Introduction to Linux Unit 1 Linux was originally developed as a free operating system for Intel x86-based personal computers. It has since been ported to more computer hardware platforms than any other operating system. 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. Linux also runs on embedded systems (devices where the operating system is typically built into the firmware and highly tailored to the system) such as mobile phones, tablet computers, network routers, building automation controls, televisions and video game consoles; the Android system in wide use on mobile devices is built on the Linux kernel. This unit provides the introductory topics to the Linux operating system, its architecture, file system, directory structure, its installation etc. 1.3 PROPRIETARY, OPEN SOURCE, AND FREE SOFTWARE Proprietary software – Proprietary software or closed source software is computer software licensed under exclusive legal right of the copyright holder with the intent that the licensee is given the right to use the software only under certain conditions, and restricted from other uses, such as modification, sharing, studying, redistribution, or reverse engineering. The owner of proprietary software exercises certain exclusive rights over the software. The owner can restrict use, inspection of source code, modification of source code, and redistribution. Vendors typically limit the number of computers on which software can be used, and prohibit the user from installing the software on extra computers. Restricted use is sometimes enforced through a technical measure, such as product activation, a product key or serial number, a hardware key, or copy protection. Vendors may also distribute versions that remove particular features, or versions which allow only certain fields of endeavor, such as non-commercial, educational, or non-profit use. Proprietary software vendors can prohibit users from sharing the software with others. Another unique license is required for another party to use the software.