At the end of 2021, it was announced that the widely used CentOS 8 - a clone of Red Hat Enterprise Linux (RHEL) - would close.

Now, CentOS 7, which is also widely used, will no longer be supported in a year's time.

In order to be able to give its users planning security, we have summarized various migration strategies in this article.

As a clone of RHEL 7, CentOS 7 shares binary compatibility with the original as well as its release cycle - and thus also the upcoming end of support on June 30, 2024.

Coinciding with the transition of Red Hat Enterprise Linux 7 from Maintenance Support 2 to Extended Life Cycle Support, CentOS 7 will thus no longer receive security updates, bug fixes or enhancements.

RHEL 7 systems will continue to receive limited technical support with the "ELS" add-on subscription, but will also no longer receive security updates and bug fixes.


Advantages of a RHEL Subscription 

If one wants guaranteed, resilient support, the use of RHEL as successor of the CentOS systems is recommended in any case.

For setting up, configuring or troubleshooting RHEL systems, there are two approaches to benefit from a subscription.

By accessing the excellent product documentation as well as the Red Hat Knowledge Base, which is maintained from numerous settled support cases, one can independently fix a large part of the arising error patterns as well as configure the system appropriately.

If a problem cannot be solved with these resources, additional engineers from Red Hat specialized for the task can be called up through the included support.


Migration from CentOS to RHEL

There is a supported migration path from CentOS 7 to RHEL 7 from Red Hat using Convert2RHEL.

Another tool, leapp, allows subsequent in-place upgrade from the new RHEL 7 systems up to RHEL 8 (and then on to RHEL 9).


Open Source as an alternative

As an open source alternative to RHEL 8 or 9, AlmaLinux is more recommended than Rocky Linux. Thus new releases of AlmaLinux 8.x and 9.x come almost at the same time with the appearance of RHEL 8.x and 9.x, while the appropriate Rocky Linux variants are published consistently one week later.

The Elevate project of Alma connects the version jump of 7 to 8 with the distribution change necessary for it, since CentOS 8 is already for longer no longer available.

Thus the jump is possible from CentOS 7 to e.g. AlmaLinux 8 or Rocky Linux 8.



While there are suitable technical open source solutions to the approaching EOL of CentOS 7, one should clarify nevertheless whether one wants to take the risks of these Community projects - as for example the missing support in the emergency - further. Finally, now would be a good time to heave the IT infrastructure on a healthy, uniform, stable and supported foundation.