Upgrading Linux Kernel in CentOS - Power Sysadmin Blog

Let’s look at how to update the Linux kernel to the latest version in CentOS as an example.

Check which version of Linux you have installed:

$ cat /etc/redhat-release

CentOS Linux release 8.2.2004 (Core)

Check the kernel version:

$ uname -r

4.18.0-193.6.3.el8_2.x86_64

The kernel version 4.18 is quite old and we will update it to 5.17.

Let’s start by connecting the ElRepo repository. This is a community repository for Enterprise Linux which provides support for RHEL, CentOS, Scientific, and Fedora.

Import the repository key:

$ rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org

And install ElRepo:

$ dnf install -y https://www.elrepo.org/elrepo-release-8.el8.elrepo.noarch.rpm

List available Linux kernels:

$ dnf --disablerepo="*" --enablerepo="elrepo-kernel" list available| grep kernel-ml

To install the latest available kernel, use the command:

$ dnf --enablerepo=elrepo-kernel install kernel-ml

Now you need to configure Linux to boot with the new kernel:

$ grub2-set-default 0

Update the grub config:

$ grub2-mkconfig -o /boot/grub2/grub.cfg

Restart your host:

reboot

Check the kernel version and make sure it has changed to 5.17:

$ uname -r

5.17.1-1.el8.elrepo.x86_64

Two versions of the kernel are currently available on the system:

$ rpm -qa | grep kernel

kernel-core-4.18.0-240.10.1.el8_3.x86_64
kernel-ml-core-5.17.1-1.el8.elrepo.x86_64

You can remove the old kernel (optional):

$ dnf remove kernel-core-4.18.0 kernel-devel-4.18.0 kernel-tools-libs-4.18.0 kernel-headers-4.18.0

Check that the old kernel version has been removed:

$ rpm -qa | grep kernel

kernel-ml-core-5.17.1-1.el8.elrepo.x86_64
kernel-ml-5.17.6-1.el8.elrepo.x86_64
kernel-ml-modules-5.17.1-1.el8.elrepo.x86_64