Before we begin, it's important to ensure that you have CentOS 7 installed and have access to a root account or an account with sudo privileges. Also, make sure that your system is updated to the latest available kernel and packages.

Installing kpatch

1. Adding the repository The first step is to add the EPEL (Extra Packages for Enterprise Linux) repository, which contains the kpatch package. This can be achieved by running the following command:

   sudo yum install epel-release
   ​

2. Installing kpatch After adding the EPEL repository, you can install kpatch using the following command:

   sudo yum install kpatch
   ​

Configuring kpatch

After installation, kpatch needs to be configured properly. The configuration varies depending on what patches or updates you want to apply to the kernel.

1. Creating a patch Kpatch allows you to create patches from diff files of changes in the kernel source code. Suppose you have a diff file named example.patch. To create a live patch, use the kpatch-build tool:

   kpatch-build example.patch
   

   This command will create a kernel module that can be loaded into the running system.

2. Loading the patch After creating the patch, you can load it into the kernel using the command:

   sudo kpatch load <patch-name>.ko
   

   This applies the patch to the running kernel without requiring a reboot

Automating and Managing Patches

To automate the update process and manage patches, you can use tools like the kpatch daemon, which monitors available patches and applies them as needed.

1. Starting the kpatch daemon The kpatch daemon can be started using the command:

   sudo systemctl start kpatch
   ​

   To set it to automatically start on system boot, use:

   sudo systemctl enable kpatch
   ​

Kernel live patching using kpatch on CentOS 7 allows administrators to apply critical security fixes and kernel updates to running systems without the need for a reboot, increasing system availability and security. The above guide walked you through the basic steps of installation, configuration, and management of kpatch. For deeper understanding and advanced configuration options, we recommend consulting the official kpatch documentation and Linux kernel documentation.