Oliver Pelz has more than 10 years of experience as a software developer and system administrator. He graduated with a diploma degree in Bioinformatics and is currently working at the German Cancer Research center in Heidelberg where he authored and co-authored several scientific publications in the field of Bioinformatics. Next to developing web applications and biological databases for his department and scientists all over the world he is administrating a division-wide Linux-based data center and has setup two high-performance CentOS clusters for the analysis of high-troughput microscope and genome sequencing data. He loves writing code, riding his mountainbike in the Black Forest of Germany and is an absolute Linux and open-source enthusiast for many years. He has contributed to several open-source projects in the past and also worked as a reviewer on the book Centos 7 High Performance. He maintains an IT tech blog at www.oliverpelz.de **********************************Acknowledgement************************************** I would like to thank my family and especially my wonderful wife Beatrice and little son Jonah for their patience and understanding for all these long working hours while writing this book. Also I would like to thank the folks at Packt Publishing for all their support and the opportunity to to write this book, it was a great pleasure for me. Last but not least I would like to thank Jonathan Hobson for writing the first edition of this book, without him no second edition of this book would have been possible. I would also like to thank all of the mentors that I’ve had over the years, especially Tobias Dykerhoff who introduced me to the whole world of Linux a long time ago and infected me with his enthusiasm about open-source and the free software movement. **********************************Dedication*********************************** This work is dedicated to my son Marlin Pelz who was stillborn on 2.10.15 just a few days before his expected date of delivery while writing the last few chapters of this book. Marlin, words can not express how much I miss you!