Preface

Welcome to CentOS System Administration Essentials. My name is Andrew Mallett, and I will be offering you expert guidance and tuition, enabling you with the skills to tame this powerful and popular Linux distribution. I have chosen to write about CentOS primarily as it will not cost you to use it, neither while learning nor during production. Additionally, CentOS closely follows the Red Hat Enterprise Linux distribution, so the skills that you learn and develop here can be put to good use across both CentOS and Red Hat. Should you be interested, your reading can act as an investment in your career by pursuing the Red Hat certification paths. Although not directly written to fit into any existing curricula, the Red Hat exams are all based on practical exercises, so the more you know and understand about the operation of Linux, the better.

CentOS stands for Community Enterprise Operating System, and even though community is such a small word, it encompasses so much. The support emanates from the community, via fora and the Linux community, to help develop the services and applications, and provide remedies to bugs that occur. The community has taken ownership of this distribution. The distribution collectively becomes stronger with the continued involvement of a growing community.

While we talk of community, I would like to thank Say Mistage (available on Twitter at @sayomgwtf) for her inspiration and doodles.

Writing about an Enterprise Linux distribution is important as we see the increase in the number of organizations deploying Linux and, as a result, require knowledgeable professionals to manage these systems. In 2013, the Linux Foundation with Dice, a specialist recruitment company, surveyed many large organizations and found the following results:

• 93 percent of the organizations polled were looking to employ Linux professionals
• 91 percent of hiring managers reported that they found it difficult to find skilled Linux administrators
• As a side note to this, it was additionally noted that salaries for Linux professionals had increased by 9 percent during the previous 12 months

With such confidence in Linux within so many organizations, the focus of this book has to be commercially driven for both myself and you, the reader. I want you to be able to improve your career prospects as well as your Linux knowledge.

Enterprise Linux distributions such as CentOS, Red Hat, Debian, and SUSE Enterprise Linux generally do not deploy the latest and greatest bleeding edge technology that you might find in home or enthusiast-oriented distributions such as Fedora or openSUSE. Rather, they allow these to be development platforms to hone and perfect the software before migrating it to the enterprise platforms some months or even years later. Enterprise Linux has to be dependable, reliable, and resilient. On top of this, it must be well supported by both the organization deploying it, as well as the backend support coming from the community or paid support teams. The very latest in software development does not lend itself well to this by definition; as they are the most recent, the knowledge of these advancements, as well as their best practices, will without a doubt take time to evolve and develop.