Introduction
The kernel is the core component of an operating system, serving as the
bridge between hardware and software. It manages system resources,
facilities communication between hardware and applications and ensures the
overall stability and functionality of the computer. Acting as a supervisor,
the kernel handles tasks such as process scheduling, memory management and
device communication. It plays a pivotal role in enabling various software
programs to run efficiently on a computer, making it an essential component
for the proper functioning of an operating system.
Steps to Update Kernel Version on CentOS/RHEL
Before updating Kernel version on CentOS/RHEL, check installed kernel
version of your system OS by following any one of the commands.
$ uname -r
$ cat /proc/version
Step 1: - Enable to latest version of EL Repository
To install the new kernel version, a new latest version of EL repository
needs to be enabled by following commands
$ sudo rpm --import
https://www.elrepo.org/RPM-GPG-KEY-elrepo.org
$ sudo rpm -Uvh
https://www.elrepo.org/elrepo-release-7.0-3.el7.elrepo.noarch.rpm
Step 2: - List All Available Kernel versions
To list all available kernek versions, execute following command
$ yum list available --disablerepo='*' --enablerepo=elrepo-kernel
Step 3: - Select Required version of the kernel to install
To install the latest version of stable long-term support kernel use
following command
$ sudo yum --enablerepo=elrepo-kernel install kernel-lt
Step 4: - Set Default Kernel Version
To set latest installed version of the kernel to load at the boot time
automatically edit grub file under /etc/default
$ sudo vim /etc/default/grub
Search for the GRUB_DEFAULT line and change it to GRUB_DEFAULT=0. This will
instruct boot loader to load default to the first kernel on the list, which
is the latest.
After saving the /etc/default/grub file execute the following command to
recreate the kernel configuration
$ sudo grub2-mkconfig -o /boot/grub2/grub.cfg
Step 5: - Reboot the system
$ sudo reboot
