It must be about 8 years now since we choose CentOS as our default operating system for Linux servers. A lot has changed since then and it has always been on my to do to write a blog post about it. Karanbir Singh announced the release of CentOS 7.4.1708 on 13/09/17. As with all CentOS 7 components, this release was built from sources hosted at git.centos.org. It also supersedes all previously released content for CentOS Linux 7, and users are highly encouraged to upgrade all systems running CentOS 7. Make sure to read the release notes before upgrading.
One month later, we were able to patch all our CentOS 7 systems and did not run into a single upgrade problem. I would say that merits a big congratulations to the whole CentOS team, and of course also all Red Hat engineers for producing a problemless and stable distribution.
In this post I’ll try to give a general overview of what CentOS is about and why you should choose for this partcular operating system.
It’s very important to keep an eye on the lifecycles of the operating systems you are managing. Good planning ensures you have enough time to migrate your applications in time before your operating systems are no longer supported.
|CentOS Version||Release Date||Full Updates||Maintenance Updates|
|3||19 March 2004||20 July 2006||31 October 2010|
|4||9 March 2005||31 March 2009||29 February 2012|
|5||12 April 2007||31 January 2014||31 March 2017|
|6||10 July 2011||10 May 2017||30 November 2020|
|7||7 July 2014||Q4 2020||30 June 2024|
CentOS 7 Repositories
There are three primary CentOS repositories (also known as channels), containing software packages that make up the main CentOS distribution:
- base – Contains packages that form CentOS point releases, and gets updated when the actual point release is formally made available in form of ISO images.
- updates – Contains packages that serve as security, bugfix or enhancement updates, issued between the regular update sets for point releases.
- addons – provides packages required for building the packages that make up the main CentOS distribution, but are not provided by the upstream.
CentOS vs Red Hat Enterprise Linux
While CentOS is derived from the Red Hat Enterprise Linux codebase, CentOS and Red Hat Enterprise Linux are distinguished by divergent build environments, QA processes, and, in some editions, different kernels and other open source components. For this reason, the CentOS binaries are not the same as the Red Hat Enterprise Linux binaries. Red Hat Enterprise Linux (RHEL) is actually also open source. But although the code is available for Red Hat users, it is not free to use. Red Hat and the CentOS project announced 7 January 2014 they were actually joining forces.
|License||FOSS – GPL and others||Commercial – RedHat EULA|
|Security||SELinux, NSS, Linux PAM, firewalld||SELinux, NSS, Linux PAM, firewalld|
|Patches/fixes||As promptly as possible given available project resources.||SLA through Red Hat|
|Support||Self-support||24x7 support through Red Hat|
|Enterprise package management||Spacewalk / Katello||Red Hat Satellite|
|Clustering||Linux-HA||Red Hat Cluster Suite (RHCS)|
|Bootloader||GRUB 2||GRUB 2|
|Graphical user interface (GUI)||GNOME 3 / KDE SC 4.10||GNOME 3 / KDE SC 4.10|
|Storage management||LVM / SSM||LVM / SSM|
|Default file system||XFS||XFS|
|Containerization||Docker, Kubernetes||Red Hat OpenShift|
|Virtual device interface (VDI)||SPICE||SPICE|
There are a lot of advantages in choosing Red Hat 7 over CentOS 7.
- Enterprise-level support
- Access to engineering resources
- Red Hat’s Customer Portal
- Latest features
But choosing Red hat also has some considerable disadvantages:
- Not free
- Administration overhead for license management
And yes, I do mention the administration overhead as a problem. This problem might not apply for everyone though. In my case though the process of ordering new Red Hat licenses or prolonging expiring licenses just takes a lot of (unnecessary) time.
So I hope my blog post gave you some additional information to make a better informed decision which operating systems are best suited for your use case. If you need professional support, Red Hat is there for you, if you feel comfortable supporting your own Linux servers, follow the CentOS rabbit.