RHCSA & RHCE Red Hat Enterprise Linux 7: Training and Exam Preparation Guide (EX200 and EX300), Third Edition (2015)

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.

About this Book

This book covers four major learning objectives: 1) a self-study guide for Red Hat exams RHCSA (EX200) and RHCE (EX300) for those who intend to take the two exams and pass them, 2) an in-class training guide for college students, 3) an on-the-job reference for administrators, programmers, and DBAs, and 4) an easy-to-understand guide for novice and non-RHEL administrators who plan to learn RHEL from scratch.

This book is divided into two sections—RHCSA and RHCE—based on exam and learning objectives. The RHCSA section covers tasks that are intended for a single system, while the RHCE section covers those that require two or more networked systems. The book has twenty-five chapters altogether that are organized logically, keeping in mind the four learning objectives mentioned above.

1. The RHCSA Section (chapters 1 to 13) covers the topics that will help the reader learn system administration tasks and prepare for the new RHCSA exam. Material presented includes local RHEL7 installation; general Linux concepts and basic commands; compression and archiving; text editor and online help; file and directory manipulation and security; processes, task scheduling, and bash shell features; package administration and yum repository; host virtualization, and network and automated installations; system boot, kernel management, systemd, and local logging; user and group administration; storage partitioning and file system build; AutoFS, swap, and ACLs; basic firewall and SELinux; network interface configuration and NTP/LDAP clients; and SSH and TCP Wrappers.

2. The RHCE Section (chapters 14 to 25) covers the topics that will help the reader learn network administration tasks and prepare for the new RHCE exam. Material presented includes automation with shell scripting; network interface bonding and teaming; IPv6 and routing setups; remote time synchronization, firewalld, and Kerberos authentication; kernel tuning, resource utilization reporting, and network logging; block storage sharing with iSCSI; file storage sharing with NFS and Samba; web servers and virtual hosting; mail transfer and DNS; and MariaDB configuration and query.

Each chapter in the book highlights the major topics and relevant exam objectives covered in that chapter and ends with a summary followed by review questions/answers and Do-It-Yourself challenge labs. Throughout the book, figures, tables, and screen shots have been furnished to support explanation. This book includes two sample exams for RHCSA and two for RHCE, and are expected to be done using the knowledge and skills gained from reading the material and practicing the exercises and challenge labs.