CentOS

CentOS (Community Enterprise Operating System) has been commonly used and totally free of charge as a Red Hat rebuild for many years. This is where Red Hat logos and branding are removed from the system and redistributed as "CentOS". This is not quite as bad as it may first seem. Red Hat uses the open source code and redistribution is totally within the remit of the GPL (GNU Public License) agreement. What you lose out on is support. So, you may well find CentOS more used within smaller business operations and academia (where external support is not as critical). Support for CentOS is available only through public forums. Of course, this means that there is no guaranteed service level available.

CentOS began its operation in 2004 and is now entering its second decade. The free of charge product it brings on the market replicates the same reliability and predictability of its Red Hat cousin. The relationship between Red Hat and CentOS was more formalized in January 2014. The governance panel at CentOS now includes Red Hat board members among their numbers.

CentOS does not release beta versions in the same way as Red Hat. This means that the latest version available from the CentOS stable is version 7.0. This will use the same kernel and version 3.10.0-123 as the RHEL 7.0 distribution. The close resemblance between CentOS and Red Hat often means that CentOS becomes a perfect study platform for those wishing to learn Red Hat and, perhaps, gain their certifications. This is certainly a very viable option and the same applies to studying this book. Although, we will be using RHEL 7.1 beta, if you want to use CentOS, this should be very similar and mostly compatible with CentOS 7.

As CentOS does not offer subscription support, this in turn affects the product life cycle. To obtain the entire 13 years of support that RHEL 7 offers, a RHEL customer will have to purchase extended support for the final 3 years coverage. This means that CentOS has repositories that will distribute updates for 10 years, resulting in the fact that CentOS 7 can continually be updated until June 2024. Not bad at all when you see it like this and all without financial cost.

You can download the latest version of CentOS without the need to create an account directly from http://centos.org/download/.