How to manage real-time kernel


The real-time kernel is currently supported on Ubuntu 22.04 LTS (Jammy) and 24.04 LTS (Noble). For more information, feel free to contact our real-time team.

Enable and auto-install


Once you enable real-time kernel, enabling some Pro services will not be possible. For a complete view of which services are compatible with real-time kernel, refer to the services compatibility matrix..

To enable the real-time kernel through the Ubuntu Pro Client, please run:

$ sudo pro enable realtime-kernel

You’ll need to acknowledge a warning, and then you should see output like the following, indicating that the real-time kernel package has been installed.

One moment, checking your subscription first
The Real-time kernel is a beta version of the 22.04 Ubuntu kernel with the
PREEMPT_RT patchset integrated for x86_64 and ARM64.

This will change your kernel. You will need to manually configure grub to
revert back to your original kernel after enabling real-time.

Do you want to continue? [ default = Yes ]: (Y/n) yes
Updating package lists
Installing Real-time kernel packages
Real-time kernel enabled
A reboot is required to complete install.

After rebooting you’ll be running the real-time kernel!

Enable and manually install


The --access-only flag was introduced in Pro Client version 27.11

If you would like to enable access to the real-time kernel APT repository but not install the kernel right away, use the --access-only flag when you enable it, as follows:

$ sudo pro enable realtime-kernel --access-only

With this extra flag you’ll see output like this:

One moment, checking your subscription first
Updating package lists
Skipping installing packages: ubuntu-realtime
Real-time kernel access enabled

To install the kernel you can then run:

$ sudo apt install ubuntu-realtime

You’ll need to reboot after installing to boot into the real-time kernel.


  • Real-time kernel is not compatible with Livepatch. If you wish to use the real-time kernel but Livepatch is enabled, pro will warn you and offer to disable Livepatch first.