The Linux kernel is the core of the operating system that manages hardware, memory, processes, and system calls.
Updating the kernel provides:
Identify the running kernel version before updating.
uname -r
Linux usually keeps older kernels as a fallback.
Refresh repository metadata to ensure access to the latest kernel packages.
sudo apt update
sudo yum makecache
Install the latest generic kernel package.
sudo apt install linux-generic
Or upgrade all packages including the kernel.
sudo apt upgrade
Install the latest kernel package.
sudo yum install kernel
Or update the entire system.
sudo yum update
List all installed kernel versions.
dpkg --list | grep linux-image
rpm -q kernel
Select which kernel version should boot by default.
List available kernels:
grub2-editenv list
Set default kernel:
sudo grub2-set-default 0
Regenerate GRUB configuration:
sudo grub2-mkconfig -o /boot/grub2/grub.cfg
Kernel changes take effect only after a reboot.
sudo reboot
Confirm the system is running the updated kernel.
uname -r
Clean up unused kernels to free disk space.
sudo apt autoremove --purge
sudo package-cleanup --oldkernels --count=2
If the new kernel causes issues:
Kernel updates and upgrades in Linux are safe and structured. New kernels are installed alongside existing ones, allowing easy rollback while improving system security, stability, and hardware compatibility.