What are Red Hat subscriptions for ?

Red Hat subscriptions allow you to register your Red Hat software in order to receive regular updates and security patches. Additionally, if you purchase a subscription with Standard support or Premium support, you will have the right to open support cases in order to get help. Some products feature a Self-support or Entry Level support level which only provides maintenance (updates) but doesn't give access to support.

As described in https://opensubs.io/en/content/6-difference-between-a-licence-and-a-subscription, Red Hat subscriptions are not licences and they do not allow you to use the software. You can always use the software, but you will not be able to automatically update the software and open support tickets if you do not have a subscription. Consequently, if your subscription expires, you can still continue to use the software, but you will not be able anymore to install additional packages, perform updates or apply security patches.

The main reason why you would want to use Red Hat software and purchase subscriptions instead of using the community equivalents are the following:

  • Subscription-based software from Red Hat boasts many certifications, with hardware vendors, as well as with software vendors. This guarantees compatibility with your hardware and 3rd party software
  • Subscription-based software from Red Hat is based on an older version of the upstream community version of the software. It is heavily tested and recent bugfixes are backported to it. This guarantees stability and robustness
  • When there is an issue with the community version of software, you will often be required to upgrade to the latest version to be able to get help from the community. With subscription-based software, you are guaranteed that the version you installed will be supported for many years. Please see the page Red Hat Enterprise Linux Life Cycle for more information on the length of support for RHEL5 through 8.

The following table shows the main differences between enterprise and community versions of software:

Enterprise software Upstream community software
Stability, robustness & security

Extensive testing by Red Hat guarantees stability, robustness and security

Security patches and bug fixes are provided during the entire life cycle of the product

Constant development

Very frequent changes (possibly multiple per day)

Code has not been through full enterprise-grade Quality Assurance

Support, service, training

Support professionals with defined SLAs and proven expertise

Experienced architects and consultants from Red Hat and from a huge partner ecosystem

Many trainings available

Excellent documentation

Self-support and community support only with no SLAs

No training, certification or consulting services from Red Hat

Upgrade paths

Supported and fully maintained and documented upgrade paths

Clear product life cycles

Upgrade paths might not exist (only migration)

Upgrades are not necessarily fully documented

The relationship between Fedora, Red Hat Enterprise Linux and CentOS

Red Hat has many products and all of them, without any exception, are open-source and have an upstream community version. For example, the following table shows a few products and their upstream community projects:

Red Hat Product Upstream community project
Red Hat Enterprise Linux Fedora
Red Hat Enterprise Virtualization oVirt
Red Hat Satellite Foreman, Katello, Puppet, Candlepin, Pulp, Hammer, etc.
Red Hat OpenShift OKD

In the specific case of RHEL, there is an additional project called CentOS which aims to provide a binary equivalent of RHEL. As discussed above, nothing prevents you from installing Red Hat Enterprise Linux and using it freely, as it is open-source software. Updates and patches are also open-source, therefore, you could manually download them from the Red Hat website and you would have a fully functional RHEL platform, albeit without support, for free. The CentOS project does exactly that, it provides an image of Red Hat Enterprise Linux that is binary compatible, as well as the automatic retrieval of updates and patches, also binary compatible. The only difference is in the removal of trademarks, change of colors, removal of certain packages and differing support of architectures.

Red Hat has terms and conditions that stipulate that when you buy at least one subscription you have the obligation to subscribe all the Red Hat products that you are running. This is to prevent customers from subscribing a single instance and using it to get support for all their other non-subscribed instances.

This is where CentOS comes in handy. You could for example subscribe only your production environment instances running on RHEL and run your other less critical environments on CentOS.

Beware that CentOS is always behind RHEL in terms of making software available. For example, RHEL8 became available in May 2019 whereas CentOS 8 became available in Septembre 2019.

Contact us if you need more information regarding Red Hat products.