Latest Linux kernels

Both RHEL-based systems and Ubuntu-based system have provide an easy way to try out new kernels. This is useful for testing new network performance enhancements.

Ubuntu

You can find the latest available 6.X kernel available for your version of Ubuntu using this command:

     apt update; apt search linux-image-6 | grep generic

Find the newest kernel you'd like to install, and then run:

     apt install linux-image-6.8.0-48-generic
     update-grub2

RHEL/Rocky etc.

The ELRepo project provides a version of the most recent 'stable' Linux kernel in rpm form that is easy to install on RHEL/Rocky based hosts.

To install the latest stable kernel, do the following:

 # install repo key
 rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org 

# for el 9
 yum install https://www.elrepo.org/elrepo-release-8.el8.elrepo.noarch.rpm

# for el 8
 yum install https://www.elrepo.org/elrepo-release-8.el8.elrepo.noarch.rpm

 # then to install kernel
 yum -y --enablerepo=elrepo-kernel install kernel-ml

If you need to build device drivers, also install this one:

 yum -y --enablerepo=elrepo-kernel install kernel-ml-devel

Then configure Grub to use the new kernel:

   grub2-set-default 0
   grub2-install /dev/sda
   grub2-mkconfig -o /boot/grub2/grub.cfg

Then reboot.

To enable BBR TCP, do:

     /sbin/modprobe tcp_bbr