Preface

Red Hat® had revised their EX200 and EX300 exams for RHCSA and RHCE certifications soon after the release of Red Hat® Enterprise Linux® version 7 in June, 2014. These exams are performance-based and present scenarios that are to be accomplished on live systems within a stipulated time. This book is written to provide you with necessary coverage of theoretical and practical information to help you pass both exams. Furthermore, this book may be used for classroom training and as a deskside reference.

Keeping in view the hands-on nature of the exams, I have included a number of step-by-step procedures to implement tasks. I recommend that you get a 64-bit computer with a minimum of one dual-core processor and built-in support for hardware virtualization to practice the exercises and labs presented in this book. I have explained the hardware, virtualization, and networking requirements in detail in the first chapter for your convenience. I also advise you to either purchase a subscription for RHEL7 or download and use either CentOS or Scientific Linux, which are 100% compatible free non-commercial versions of RHEL.

I suggest you study the material presented in each chapter thoroughly before proceeding to the hands-on stuff. I have provided several review questions with answers at the end of each chapter. Take the quiz and then attempt the Do-It-Yourself (DIY) challenge labs offered thereafter. I have not furnished solutions to these labs intentionally, as I am confident that the knowledge and skills you would have gained by that time will be sufficient to accomplish the labs on your own. And in essence, this is what I want you to eventually get at. Once an entire section is finished—material read and understood, exercises performed, review questions completed, and DIY challenge labs accomplished—review the entire section quickly and then attempt the respective sample exams provided in the appendices.

While performing exercises and labs, if a command does not produce the published result, I ask that you check the message the command has generated and consult relevant log files. Minor issues, such as a wrong path, prevent commands from being executed correctly. Sometimes, there are syntax errors in the command construct. You might have to make appropriate modifications to your settings in order to make the command work. RHEL manual pages prove helpful and useful in comprehending commands and their syntaxes.

There are four areas I suggest you focus in order to develop expertise with RHEL (CentOS or Scientific Linux for that matter), as well as to prepare yourselves for the exams: 1) grasping concepts; 2) mastering implementation procedures, exercises, and labs; 3) learning commands, understanding configuration files, and knowing service daemons; and 4) being able to troubleshoot and resolve problems. An excellent understanding of which command involves which options and updates which files, which daemon provides what services, etc. should also be developed. This way you will have a better overall understanding of what exactly happens in the background when a command is executed. This book attempts to provide that knowledge too. Troubleshooting becomes easier when concepts are clear and working knowledge is solid.

I am maintaining www.getitcertify.com where I add errata, additional exam information, and links to useful resources. I encourage you to visit this website.

At the end, I would like to request for your feedback sent to my personal email asghar_ghori2002@yahoo.com about anything good or bad in the book, including any grammatical or technical errors or mistakes. Try to be as specific as possible in your description. Improvement is a continuous process and I am sure your feedback will help me write a better and improved next edition.

Good luck in your endeavors.

Asghar Ghori / March 2015 / Toronto, Canada