If you don’t know, you are not alone. When we get service inquiries, our customers often are unclear on the exact version of Linux they are using. Fortunately, you can use these simple commands to get CentOS to show you the version numbers.
The easiest way to check your CentOS version is via the command line.
Login to your CentOS server using SSH and run the following command:
You may also use:
This should return the following CentOS version information:
CentOS release 6.2 (Final)
CentOS version history follows that of Red Hat but it could be delayed, which is just one of a few things you should know before running a CentOS server.
Let’s break this down:
CentOS – This is your Linux distribution. This may seem obvious but in doing outsourced support, we sometimes find surprises.
6.2 – There are two parts of this version number. 6 is the major release version for this Linux distribution. The 2 represents the second update for this release. Red Hat, Fedora and CentOS Linux distributions use this version system.
Know that you know your CentOS version, you may also want to check what kernel is running on your CentOS server. You can check which kernel you are using by running:
This will return:
Linux office.rackaid.net 2.6.32-220.2.1.el6.x86_64 #1 SMP Fri Dec 23 02:21:33 CST 2011 ×86_64 ×86_64 ×86_64 GNU/Linux
This is the kernel that is actually running on your server. There you could be newer kernels installed on your CentOS server but not actually running. You can list the installed kernels using yum or rpm. You can then see which kernel will start on boot by checking your /etc/grub.conf.
If you run a CentOS server, keeping track of CentOS versions is important. The best way to do this is to follow the CentOS web site so you can stay on top of your chosen Linux distribution.
Also, be sure to check out the 6 things you should know about CentOS Linux.