Versions. Versions. Versions.

Learning how to check your Red Hat version numbers is easy — If you know where to look.

Check /etc/redhat-release

Most Red Hat-based distributions should have a file called redhat-release. You can find it in:

cat /etc/redhat-release

This should return the version you are using. Note that this file can be manually changed or updated but provided that someone has not modified this file, the information should be accurate. On a RHEL 5 system you will see something like this when you check your Red hat version:

[root@alpha ~]# cat /etc/redhat-release 
Red Hat Enterprise Linux Server release 5.11 (Tikanga)

This shows the serer is running RHEL version 5 Release 11.

Linux Versions
Linux distributions often have “versions”. Versions are things like Red Hat 7.3, RHEL 3, or RHEL 5. These represent major releases. When someone asks what version of Red Hat you are using, you would likely reply with RHEL 5, 6 or 7 depending on your version.

Linux Updates
RHEL has updates between major releases.

When you check your redhat version,  you will see something like 5.11. This means you are running update 11 for RHEL 5. Updates are major package releases from Red Hat. You should always use the latest update for your RHEL version.


Lastly, I want to touch on errata. Errata are simply bug fixes and security updates released by Red Hat between major updates.  Patches can arrive at any time and for a production server, you want to patch them as quickly as possible.

Keeping your system fully patched with errata is essential for security. Unfortunately, some errata may interfere with control panels like cPanel, Ensim, or Plesk. So you may need to check with your control panel vendor before rushing to apply the latest bug fix.

Not all errata apply to your server. For example, when we secure systems we remove 100’s of unnecessary software items; this reduces your exposure to potential security problems. In fact, many of the errata that are released daily deal with desktop, GUI, and similar type software often not found on properly secured servers.

Web Software Versions

A major source of confusion with RHEL are version numbers for software like PHP, MySQL and Apache.   Red Hat often backports bug and security fixes for items like PHP.   So while the version number may not change, the software is actually secure provided you have the latest patches.

Similar version issues arise with MySQL, Apache, Sendmail, and other major programs. If you are using a control panel, the ability to use a third party solution or manually use the latest Apache or PHP release may be limited. It is best to check with a system administrator familiar with your control panel before updating to a version not released by Red Hat.

Using your redhat-release file, you can easily check your red hat version and update number. This information is very helpful for technical support staff as well as knowing if you are up to date with the latest patches. Having this info can help you quickly determine if software will be compatible with your system. Keeping on top of errata can keep your system secured and running smoothly.