Chapter 1: RHCE Prerequisites

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Overview

The Red Hat exams are an advanced challenge. As both the RHCE and RHCT courses have a number of prerequisites, this book assumes that you know some basics about Linux. This chapter covers the prerequisite topics for Red Hat's RH300 course in a minimum of detail, with references to other books and sources for more information. It also covers the related prerequisites as defined in the Red Hat Exam Prep guide. Unlike in other chapters and other books in this series, the questions include a number of 'zingers' that go beyond this chapter's content. That is the only way to see if you have the prerequisite skills necessary for the remaining chapters.

If you're serious about the RHCE or RHCT exams, this chapter should be just a review. In fact, this chapter is far from comprehensive. However, it is okay if you do not feel comfortable with a small number of topics in this chapter. In fact, it's quite natural that many experienced Linux administrators don't use every one of the prerequisite topics in their everyday work. Many candidates are successfully able to fill in the gaps in their knowledge with some self-study and lots of practice.

If you're new to Linux or Unix, this chapter will not be enough for you. It's not possible to detail the commands listed in this chapter, at least in a way that can be understood by newcomers to Linux and other Unix-based operating systems. Such descriptons require several hundred pages in other books, and would take away from the skills that you need for the Red Hat exams. If after reading this chapter you find a need for more detailed information, please refer to one of the following guides:

• Red Hat: The Complete Reference, Enterprise Linux & Fedora Edition, by Richard Petersen and Ibrahim Haddad (McGraw-Hill/Osborne, 2004), provides a detailed step-by-step guide to every part of this operating system. After reading the book you have in your hands, if you want additional exercises in Red Hat Enterprise Linux, this Complete Reference is the book.

• Hacking Exposed Linux, Second Edition: Linux Security Secrets and Solutions, by Brian Hatch and James Lee (McGraw-Hill/Osborne, 2003), gives you a detailed look at how you can secure your Linux system and networks in every possible way.

• Linux Programming: A Beginner's Guide, by Richard Peterson (McGraw-Hill/Osborne, 2001), takes a fundamental look at the scripts you need to administer Linux professionally and customize tools such as the GNOME and KDE GUIs for your users.

• Mastering Red Hat Linux 9, by Michael Jang (Sybex, 2003), also provides a detailed guide to the operating system that provides the foundation for Red Hat Enterprise Linux 3.

Critical to a Linux administrator is knowledge of one or more text editors to manage the many configuration files on a Linux system. The Linux filesystem hierarchy organizes hardware, drivers, directories, and, of course, files. You need to master a number of basic commands to manage Linux. Printer configuration can be a complex topic. Shell scripts enable you to automate many everyday processes. Security is now a huge issue that Linux can handle better than other operating systems, both locally and on larger networks such as the Internet.

As an administrator, you need a good knowledge of basic system administration commands, TCP/IP configuration requirements, and standard network services. While the RHCE and RHCT exams are by and large not hardware exams, some basic hardware knowledge is a fundamental requirement for any Linux administrator.

This is not a book for beginners to Linux/Unix-type operating systems. Some of what you read in this chapter may be unfamiliar. Use this chapter to create a list of topics that you may need to study further. In some cases, you'll be able to get up to speed with the material in other chapters. But if you have less experience with Linux or another Unix-type operating system, you may want to refer to the aforementioned books.

If you're experienced with other Unix-type operating systems such as Solaris, AIX, or HP-UX, you may need to leave some defaults at the door. When Red Hat developed their Linux distribution, they did a number of things that may not seem completely consistent with Unix standards. When I took RH300, some students with these backgrounds had difficulties with the course and the RHCE exam.

For the purpose of this book, I'll be running most commands as the Linux administrative user, root. Logging in as the root user is normally discouraged unless you're administering a computer. However, since the RHCE and RHCT exams tests your administrative skills, it's appropriate to run commands in this book as the root user.

There are several additional prerequisite skills as defined in the Red Hat Exam Prep guide. They are straightforward, but belong in other chapters. In Chapter 6, I'll show you how to configure an e-mail client and use Mozilla to browse online. In Chapter 7, I'll show you how to use the lftp command as a client.

Inside The Exam

Prerequisite Skills

For the RHCE and RHCT exams, the skills outlinedinthischapteraregenerallyminimum requirements. For example, while you might not see a question on the vi editor, you will need to know how to use vi on at least the Troubleshooting and System Maintenance exam. While it's not a requirement to know how to pipe the output of dmesg to the less command, it's a very useful tool that can help you identify problems on the Troubleshooting or Installation portions of either exam.

But remember, there is more than one way to do most everything in Linux. While it's a good idea to learn all of these 'prerequisite' skills, you don't have to know everything in thischapter.Inmostcases,it'sokayifyouhave other ways to edit or otherwise configure your RHEL3system.Asthereisnolongeramultiple choicecomponenttotheRedHatexams,don't worry about the dozens of switches for certain commands. Focus on results, not trivia.

Using Other Versions of Red Hat

For the purpose of this chapter, you can use Red Hat Linux 9 or Fedora Linux 1 to test your knowledge of basic commands. There are trivial variations in a few commands. For example, fdisk now interprets the size of a partition slightly differently. (For more information, see the RELEASE-NOTES-i386-en file in the /usr/share/doc/redhat-release-3 directory or the RHEL 3 documentation at www.redhat.com.) For those of you with more advanced hardware, the Red Hat exams are based on PCs built with Intel 32-bit CPUs. That means you'll be using the Linux kernel and associated softwarethathasbeencustomizedforthisCPU.

In future chapters, I will highlight some of the differences between Red Hat Enterprise Linux 3 (RHEL 3) and Red Hat Linux 9. This should help students who are using the freely availableRedHatLinux9distributiontostudy for the RHCE and RHCT exams. Generally, you'll be able to update your Red Hat Linux 9 system to the RHEL 3 software. If you're using Fedora Linux 1 or above, the process may be more difficult, as RHEL 3 is based on Red Hat Linux 9.

Fortunately,thereisafreelyavailableversion of RHEL 3 from the Community Linux group, at www.caosity.org. It's available as packages processedfromthesourcecodeorasathree-CD setofISOimages.Itincludesallavailablenon-proprietary packages from Red Hat Enterprise Linux 3 server.

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