INTRODUCTION

Greetings and welcome to the wonderful world of Systems Administration. After working through this course you will hopefully have some appreciation of the complexities, hassles, intricacies, pitfalls, purpose and fun of being a Systems Administrator.

Systems Administration is not a science! There is no law handed down to Moses by a burning bush that states "You shalt.....". Each situation has to be dealt with on its own merits and according to the environment at the time. This course won't tell you the way to fix a problem. Instead (hopefully) it will help you develop the ability and knowledge required to decide between the plethora of choices and follow the option that is best for your site at any particular time.

Exercises and Review Questions

Throughout each section of this course there are a number of Exercises that have been designed to test your understanding of the concepts introduced. It is suggested that you try these exercises when you meet them. Each section finishes with a set of Review Questions. These questions form the basis of the tutorial work you should complete with each section.

Solutions to both the exercises and review questions are included at the end of the course.

Format and Fonts

The course follows a number of simple formatting styles that should assist you in reading it.

Readings

Any text of the following format

Reading Where the reading is taken from

Purpose Explanation of why the reading is useful.

refers to aditional reading material. When you come across text of this format you should complete the associated reading before progressing.

Exercises

Text in the following format

Exercise 1.1 text of a question

are exercise questions included to test your understanding of a concept. It is important that you complete the exercise when you first come across this text.

Computer Input and Output

Text in the following format

        bash> ls
        Mail            core            masters.tar.z   
        rcos.uu         telnet.doc      Masters        
        dead.letter     mbox            research

is used to signify text produced or entered into a computer. Text in bold has been entered by a user. Text in the normal font is output by the computer.

Any text that is in italics is meant as a symbol that should be replaced by a real value.

For example:

        ls filename
        filename is a symbol that should be replaced with the name of a file.

Course Source

The primary source of this course is for the subject 85321, Systems Administration offered by the Department of Maths & Computing of the Central Queensland University. Table 0.1 summarises how the course should be covered for that subject.

        Week    Sections        Topic

        1    1 and 2    Introduction to Systems Administration and some basic UNIX
        2       3       UNIX Shell Programming
        3       4       Advanced UNIX Use
        4    5 and 6    Systems Administration Theory and Users
        5    7 and 8    File Systems and Backups
        6       9       Starting Up and Shutting Down
        7   10 and 11   Terminals and Printers
        8       12      Unix Network Basics
        9       13      More Networking
        10      14      Security
        11      15      The Kernel
        12      16      cron, Accounting and Quotas
        13      17      Professional Issues

                Table 0.1. Timetable for the 85321 course.

Resource Materials

The extra reading material referred to is from the Resource Materials book that is provided to students of the subject 85321.

Section Descriptions

The following sections briefly describe the individual sections of this course.

Section 1: Foundations

Section 1 provides an introduction to the role and responsibilities of a Systems Administrator. It also introduces a number of basic concepts regarding operating systems, UNIX and a brief introduction to the vi editor.

Section 2: Basic UNIX

The aim of this section is to provide an introduction to how to use the UNIX operating environment. It examines UNIX command format, the role of the shell, file and directory manipulation, various UNIX commands and the on-line help system.

This section can be skipped if you are already an experienced user of the UNIX operating system.

Section 3: Shell Programming

Much of what a Systems Administrator does includes writing and being able to understand shell programs. This section examines all of the basic shell programming knowledge necessary for a Systems Administrator. The section only discusses the syntax of the Bourne shell.

If you are already an experienced writer of Bourne shell programs you may skip this section.

Section 4: Advanced Unix Use

Section 4 rounds off the UNIX user information. It examines more advanced shell programming, advanced commands including awk and sed and regular expressions.

Section 5: Systems Administration Theory

This section examines some of the generic, hardware independent tasks that a Systems Administrator must complete including management, policies, procedures, communication with the users, and most importantly, documentation.

Section 6: Users and Accounts

Computers were created so people could use them to do work. Section 6 examines the procedures and files involved in letting people use a UNIX machine. It examines how to add and delete users and where and what information is stored about users.

Section 7: File Systems

All operating systems store information for future use onto disk drives. This section examines how the UNIX operating system stores and retrieves information from disk drives.

Section 8: Backups

Section 8 examines what might be the most important task that a Systems Administrator is responsible for and one that is usually neglected, the backing up of important data.

Section 9: Starting Up and Shutting Down

The UNIX operating system is a complex beast. This section examines the process the machine goes through when it boots and when it is shut down. It also examines the responsibilites of the Systems Administrator with regards starting a system and shutting it down.

Section 10: Terminals

A computer must not only store information but it must also provide methods by which users can access the information. Section 10 examines how terminals are added to a UNIX machine.

Section 11: Printers

In addition to showing how to add a printer to a UNIX machine. Section 11 also examines the software systems UNIX uses to implement printer support.

Section 12: Unix Network Basics

Networking is an increasingly important part of computing. Section 12 introduces you to the basics of networking within the UNIX environment.

Section 13: More Networking

Section 13 extends the coverage of networking to including additional features like NFS. It also provides some insight into adding hosts to a network and other more advanced networking topics.

Section 14: Security

Section 14 examines some of the security problems and issues related to the Unix environment and provides solutions and tips on how to solve them.

Section 15: The Kernel

The kernel is the central work horse of the operating system. Section 15 discusses the kernel, its responsibilities, and how the Systems Administrator can control it.

Section 16: `cron`, Accounting and Quotas

Section 16 brings together and discusses the

cron system,
The method by which the Systems Administrator can schedule tasks to be carried out automatically at set times.
accounting,
The methods by which the UNIX operating system allows you to track what is being done to your system and by whom.
quotas.
Methods by which limitations can be placed on what users can do and the resources they can consume.

Section 17: Professional Issues

Section 17 discusses, to some part, life as a professional Systems Administrator. Topics covered include

sources of information including books and magazines, and
professional organisations for Systems Administrators.

Solutions

The solutions for both the review questions and the section exercises are included at the end of the course.

Acknowledgements

This course has developed over a couple of years and has been improved by the efforts and feedback of a number of people. This particular version of the course has benefited from the efforts of Peter Hardy, Shaun Teeney and Peter Van Heck, three CQU distance students who trialed the course (and the subject) during late 1994.

Extra special thanks must go to Mary Cranston and Elizabeth Tansley who provided invaluable assistance, both with proof-reading and as a source of many useful ideas.

I would also like to thank three people who have made material contributions to the course. Janet Jackson for her piece in Section 5 on communicating with users. Kenny Paul for the picture on the front cover and Mary Cranston (again) for the awk documentation included in the resource materials book.

Trademarks

UNIX and various other trademarks are all owned by their various owners. While every attempt has been made to guarantee its correctness there is no warranty about the information in this document.

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David Jones (author)
Chris Hanson (html 12/09/96)