The Red Hat RHCT and RHCE exams are designed to test candidate qualifications as Linux systems technicians and engineers. If you pass either of these exams, it's not because you've memorized a canned set of answers-it's because you have a set of Linux administrative skills and know how to use them under pressure, whether it be during an exam or in a real-world situation.
While this book is organized to serve as an in-depth review for the RHCT and RHCE exams for both experienced Linux and Unix professionals, it is not intended as a substitute for Red Hat courses, or more importantly, real-world experience. Nevertheless, each chapter covers a major aspect of the exam, with an emphasis on the "why" as well as the "how to" of working with and supporting RHEL as a systems administrator or engineer. As the actual RHCT and RHCE Exam Prep guide (www.redhat.com/rhce/examprep.html) changes with every release of RHEL (and even sometimes between releases), refer to the noted URL for the latest information. (Throughout the book, I often refer to the RHCT and RHCE Exam Prep guide as the Red Hat Exam Prep guide, even though there are Red Hat exams for certifications other than the RHCT and RHCE.)
Red Hat says it's important to have real-world experience to pass their exams, and they're right! However, for the RHCT and RHCE exams, they do focus on a specific set of Linux administrative skills, as depicted in the Red Hat Exam Prep guide. This book is intended to help you take advantage of the skills you already have-and more importantly, brush up in those areas where you may have a bit less experience.
This book includes relevant information from Red Hat Enterprise Linux 5 (RHEL 5). There are significant changes from Red Hat Enterprise Linux 4; As of this writing, Red Hat even offers a course detailing the differences (RHUP 304 and RHUP 305). Several key differences between RHEL 4 and RHEL 5 include:
A new hardware detection model. The udev system readily supports automatic mounting and configuration of a wide variety of devices.
Multicore support. Fundamental to effective virtualization, multicore CPUs can help multiple operating systems run simultaneously on the same physical system. Red Hat includes Xen in RHEL 5 to take advantage of the latest multicore CPUs.
Logical Volume Management (LVM), version 2, which supports smoother resizing of filesystems.
Software RAID now supports more modes, including RAID 6. The associated tool is more flexible.
NFS supports "stateless" network and loopback images.
yum replaces Up2Date for repository and package management as well as updates.
The Network Manager incorporates improvements in wireless networking and more, which eases administration on the desktop.
SELinux is now easier to use and administer. The descriptions in the Security Level Configuration tool are improved, and sealert -b browser can help you diagnose many SELinux-related issues.
There are many more key features; those that I believe are relevant to the RHCT and RHCE exams, as defined by the publicly available course outlines and the Exam Prep guide, are also included in this book.
While it's a risky practice in service, it is fastest to administer RHEL during the exam by logging into the root user account. The command prompt and PATH assume use of that account. When you're logged into the root account, you'll see a command line prompt similar to:
As the length of this prompt would lead to a number of broken and wrapped code lines throughout this book, I've normally abbreviated the root account prompt as:
Be careful. The hash mark (#) is also used as a comment character in Linux scripts and programs; for example, here is an excerpt from /etc/inittab:
# Default runlevel. The runlevels used by RHS are:
When logged in as a regular user, the prompt is slightly different; for user michael, it would typically look like the following:
Similarly, I've abbreviated this as:
There are a number of command lines and code interspersed throughout the chapters.
At the end of the introduction, you will find an Exam Readiness Checklist. This table has been constructed to allow you to cross-reference the official exam objectives with the objectives as they are presented and covered in this book. The checklist also allows you to gage your level of expertise on each objective at the outset of your studies. This should allow you to check your progress and make sure you spend the time you need on more difficult or unfamiliar sections. References have been provided for the objective exactly as the vendor presents it, the section of the study guide that covers that objective, and a chapter and page reference.
For this series, we've created a set of chapter components that call your attention to important items, reinforce important points, and provide helpful exam-taking hints. Take a look at what you'll find in every chapter:
Every chapter begins with the Certification Objectives-the skills you need to master in order to pass the section on the exam associated with the chapter topic. The Objective headings identify the objectives within the chapter, so you'll always know an objective when you see it.
Exam Watch notes call attention to information about, and potential pitfalls in, the exam. These helpful hints are written by authors who have taken the exams and received their certification-who better to tell you what to worry about? They know what you're about to go through!
Practice Exercises are interspersed throughout the chapters. These are step-by-step exercises that allow you to get the hands-on experience you need in order to pass the exams. They help you master skills that are likely to be an area of focus on the exam. Don't just read through the exercises; they are hands-on practice that you should be comfortable completing. Learning by doing is an effective way to increase your competency with a product. Remember, the Red Hat exams are entirely "hands-on;" there are no multiple choice questions on these exams.
|On the Job|| |
notes describe the issues that come up most often in real-world settings. They provide a valuable perspective on certification- and product-related topics. They point out common mistakes and address questions that have arisen from on-the-job discussions and experience.
Inside the Exam sidebars highlight some of the most common and confusing problems that students encounter when taking a live exam. Designed to anticipate what the exam will emphasize, getting inside the exam will help ensure you know what you need to know to pass the exam. You can get a leg up on how to respond to those difficult-to-understand labs by focusing extra attention on these sidebars.
Scenario & Solution sections lay out potential problems and solutions in a quick-to-read format.
The Certification Summary is a succinct review of the chapter and a restatement of salient skills regarding the exam.
The Two-Minute Drill at the end of every chapter is a checklist of the main points of the chapter. It can be used for last-minute review.
The Self Test offers "fill in the blank" questions designed to help test the practical knowledge associated with the certification exams. The answers to these questions, as well as explanations of the answers, can be found at the end of each chapter. By taking the Self Test after completing each chapter, you'll reinforce what you've learned from that chapter.
The Lab Questions at the end of the Self Test section offer a unique and challenging question format that requires the reader to understand multiple chapter concepts to answer correctly. These questions are more complex and more comprehensive than the other questions, as they test your ability to take all the knowledge you have gained from reading the chapter and apply it to complicated, real-world situations. Most importantly, the Red Hat exams contain only lab type questions. If you can answer these questions, you have proven that you know the subject!
If you'd rather take an electronic version of the Self Test questions and answers, these can also be accessed online through the book's Online Learning Center. These online exams should not stand in for an actual practice test and are not test simulations. You should complete the practice exams printed at the back of the book for a more accurate simulation of the live exam and the exam environment. The bonus content accompanying the book can also be located at the Online Learning Center.
All you need to access the Online Learning Center is an Internet connection and the following URL: http://highered.mhhe.com/sites/0072264543/.
The site also contains two Appendixes that accompany the book, available for download:
"Installing Red Hat Enterprise Linux 5"
"Studying with a Virtual Machine"
To access the bonus content once you have located the site, select View Student Content or click Returning Users and you should have access to all the available material. Use the drop-down menu to navigate the site.