CentOS was launched in 2004 and is distributed under the GNU General Public License (GNU GPL). It is a stable, predictable and easy to use Linux distribution, with a growing community behind it. CentOS is short for “Community Enterprise Operating System”. The CentOS Linux distribution is based on the source code of the commercial license Red Hat Enterprise Linux (RHEL).
As part of the Linux family, CentOS is an open source Unix-like operating system based on the Linux kernel — released by Linus Torvalds in 1991. CentOS server is one of the most used web servers in enterprises and organizations. Its many features have positioned CentOS in the Top 3 of the most used Linux distributions, among other popular Linux distributions such as Ubuntu and Debian.
However, CentOS 8 will be the last version of this Linux distro. In September 2019, Red Hat announced that CentOS would be replaced by a CentOS rolling release: CentOS Stream. This shift means that the life cycle of the latest CentOS distribution, released last year, will end on December 31, 2021. Nevertheless, CentOS Linux 7 distribution will continue, as scheduled, until 2024. The timeline is summarized as follows:
- CentOS Linux 7 distribution: updates until June 30, 2024.
- CentOS Linux 8 distribution: updates until December 31, 2021.
- CentOS Stream 9 launch date: Q2 2021 (as part of the RHEL 9 development).
What’s CentOS Stream?
CentOS Stream is an upstream development platform for Red Hat Enterprise Linux. Red Hat expects this distribution will be useful for the community, as a stable ABI/API for testing and development. It can be downloaded, used, studied, modified and redistributed for free (with the exception of CentOS trademarks owned by Red Hat). This platform aims to take advantage of open-source innovation for shaping upcoming stable RHEL releases.
Rocky Linux, an alternative to CentOS (by Gregory Kurtzer)
The focus shift from CentOS Linux to CentOS Stream has pushed the founder of the CentOS project, Gregory Kurtzer, to start a new Linux distribution called “Rocky Linux”. This new enterprise-ready distribution will be a real replacement for CentOS. But its release date is yet to be determined.
Rocky Linux aims to continue the community-supported distribution based on RHEL, after the discontinuation of CentOS 8 by December 2021. As the new strategy of Red Hat entails numerous problems across the CentOS community. Nevertheless, Rocky linux isn’t affiliated with Red Hat.
CentOS Linux and Red Hat Enterprise Linux (RHEL)
CentOS is a community-supported distribution built from the source code of the Linux commercial distribution, Red Hat Enterprise Linux. As Red Hat uses open source software (published under a GPL) for building their product, they must make their source code available to the public. As a result, CentOS is functionally compatible with Red Hat Enterprise Linux, because the main changes consist in removing vendor branding and artwork.
Nevertheless, CentOS doesn’t have Red Hat’s certifications, as it is only based on its source code. The CentOS project creates binary packages from the publicly available source packages provided by Red Hat, so that anyone can use them for free. However, there may be some differences between the packages distributed by Red Hat and CentOS, since some changes aren’t made public.
Since 2014, Red Hat has sponsored the CentOS project in order to help establish a proper platform for the open source developers that integrate technologies using CentOS. So, in that same year, developers from Red Hat and CentOs came together in the Governing Board, which is now in charge of managing the distribution and the different working teams involved. This Governing Board is composed of original members of the CentOS project and Red Hat employees.
What’s the CentOS project?
The CentOS project is the organization in charge of managing the platform’s development. It goes beyond the operating system and provides resources for other groups to make the development of tools based on CentOS easier. Moreover, the CentOS project aims to establish CentOS Linux as a leading community platform for emerging open source technologies from other projects.
Special Interest Groups (SIGs)
Special Interest Groups (SIGs) are small work teams within which certain members of the CentOS community focus on specific issues in order to raise awareness, enhance the Linux distribution and optimize functional aspects (such as infrastructure or documentation). Some examples of active SIGs are ArtWork, Core and Virtualization.
CentOS main features
As CentOS is based on the source code of Red Hat Enterprise Linux, both operating systems share many features.
Stable Linux distribution
CentOS counts on a committed community of developers who keep it updated and ensure compatibility both with new software and old applications. Besides, core developers are supported by an active community of volunteer users around the world — system administrators, network administrators, Linux enthusiasts, etc — that test releases, rebuild updates and provide support.
High performance & availability
It offers great performance and high-availability using KVM (Kernel-based Virtual Machine) for virtualization.
High level of security
Red Hat’s security team proactively detects vulnerabilities and guarantees a high level of security. Besides, CentOS includes the kernel extension SELinux (Security Enhanced Linux).
Regular updates and support
CentOS versions are regularly updated, approximately every 6 months, and are supported for 10 years.
CentOS versions are based on each equivalent RHEL version. So, each CentOs version is named under the same version number and timestamp as its Red Hat Enterprise Linux equivalent. The timestamp of each version corresponds to the year and month of the equivalent version released by Red Hat. For instance, the version 8 of CentOS is named “CentOS 8.0-1905” because RHEL 8.0 was released in May, 2019.
Version updates are implemented from RHEL to CentOS with a delay of between two and six weeks. A new major CentOS version is released approximately every 2 years and each of them is supported for 10 years. Besides, as mentioned above, versions are regularly updated every 6 months, approximately.
|CentOS version||Release date||Full updates||Maintenance updates|
|3||March 19, 2004||July 2006||October 2010|
|4||March 9, 2005||March 2009||February 2012|
|5||April 12, 2007||January 2014||March 2017|
|6||July 10, 2011||May 2017||November 2020|
|7.0-1406||July 7, 2014||August 6, 2020||June 2024|
|8.0-1905||September 24, 2019||December 31, 2021||December 31, 2021|
Latest version: CentOS 8.0-1905
CentOS 8 is the latest major version, released in September 2019. It fully supports the following architectures: x86-64, POWER8 and 64-bit ARM. As for the kernel, CentOS 8.0-1905 is based on the Linux 4.18 kernel.
Minor versions of CentOS Linux 8 have been released later on:
- CentOS 8.1-1911: released on January 15, 2020. RHEL 8.1 was released on November 5, 2019.
- CentOS 8.2-2004: released on June 15, 2020. RHEL 8.2 was released on April 28, 2020.
However, as mentioned before, CentOS 8 end-of-life will arrive on December 31, 2021. As CentOS Linux will be replaced by CentOS Stream.
More details about CentOS.