Introduction

CentOS is a popular fork, or derivative, of the Red Hat Enterprise Linux distribution.

CentOS 7.6 is a minor update and was published in December 2018. It includes updates and changes, including support for newer software and server technology. This guide will walk you through upgrading and updating the current version to the latest CentOS release.

cat /etc/redhat-release

Step 2: Verify data and backups

Backing up important server data should be done before running a operating system upgrade. Take a moment to verify your system backups.

Step 3: Check for available updates

Check available CentOS updates with the command:

sudo yum check-update

The system will display a list of available updates, including the core operating system updates. Scan through these to make sure everything is in order.

A good habit is to scan for software that you’ve specifically configured or installed. If you see a familiar package listed, it can indicate that there are updates or changes you’ll want to be aware of. You can research the upgrades to software packages as needed, depending on your system configuration.

Step 4: Package manager cleanup

As the yum package manager updates your system and software, it accumulates additional listings and downloaded data.

To clear these out of your system use the terminal command:

sudo yum clean all

Reboot the server with:

# reboot

This will clear the caches and lists in the local yum repositories. This can help speed the update process, and it can also help prevent issues.

Step 5: Update CentOS

Enter the command into the terminal:

sudo yum update

The system should give you a listing of the packages to be downloaded, as well as the disk space required. The system will prompt you to confirm this is OK – press y, and the system will continue with the download and installation.

cat /etc/redhat-release