Updating Your CentOS Server to the Newest Release
Keeping your server’s OS up to date with the latest patches and updates is critical to ensuring your server’s health and security. Often, as possible threats, exploits, and security holes are identified, the CentOS team releases updates to eliminate those potential risks, similarly to your home computer’s periodic updates.
As of December 2010, version 5.5 is the most recent CentOS release. If you’re not running CentOS 5.5, these steps will show you how to update your server. If you’re not sure what version of CentOS your server uses, see Determine Your Server’s Fedora or CentOS Version.
Note: Making modifications to your Server’s Operating System can cause any custom software, services, or applications to stop functioning or render your server inoperable. Always back up all of your server’s data before updating.
You will need to SSH into the server. If you need to brush up on that, check out this article first.
Once you log in, check to see if there are any updates to install by typing the following command, and then pressing Enter:
yum list updates
A list similar to this displays:

This only shows us that there are a lot of updates available. To actually install them, type the following command, and then press Enter, but make sure you back up ALL data first:
yum update
Your server downloads and installs the updates. You may need to answer yes to a few questions about permissions by typing y and then pressing Enter.

Once the process has completed, you need to reboot the server for the changes to take effect. Type the following command, and then press Enter:
reboot
After logging back in, verify the update by asking the OS to display it’s current version:
cat /etc/*release*
If all went well, you should see CentOS release 5.5 (Final) as the output of that command.
Comments are closed.
11 min expected wait time