How to enable Real-time Ubuntu#

Real-time Ubuntu is supported on specific Ubuntu releases. To

find out more about the supported Ubuntu versions and what kernel variants are available, refer to the supported releases page.

Attach your subscription#

If you have not yet attached your machine to an Ubuntu Pro subscription, you will need to do so in order to enable Real-time Ubuntu. You can do so by running the following command:

sudo pro attach

And follow the instructions in your terminal window. For a more complete guide to the attach process, refer to our how to attach guide.

Make sure pro is up-to-date#

All systems come with pro pre-installed through the ubuntu-advantage-tools package. To make sure that you’re running the latest version of pro, run the following commands:

sudo apt update && sudo apt install ubuntu-advantage-tools

Important

Once you enable Real-time Ubuntu, enabling some Pro services will not be possible. To see which services are compatible with the real-time kernel, refer to the services compatibility matrix.

If you try to enable Real-time Ubuntu while an incompatible service is already enabled, the Pro Client will inform you and offer to disable that service.

Enable and install automatically#

The Real-time Ubuntu kernel package is installed using the APT package manager when you enable realtime-kernel through the Pro Client.

If you want to access the repository but not install the package immediately, skip to Install and enable manually.

Otherwise, select the correct version for your OS and processor, and use the corresponding command below:

sudo pro enable realtime-kernel

Caution

The generic Real-time kernel is not intended for Raspberry Pi. Using the Pro Client to install it on these platforms will make your system unusable.

For Raspberry Pi 4 and 5:

sudo pro enable realtime-kernel --variant=raspi

For 12th Gen Intel® Core™ processors:

sudo pro enable realtime-kernel --variant=intel-iotg

You will need to acknowledge a warning, then you will see a confirmation message like the following that the Real-time Ubuntu package has been installed:

One moment, checking your subscription first
Real-time kernel cannot be enabled with Livepatch.
Disable Livepatch and proceed to enable Real-time kernel? (y/N) y
Disabling incompatible service: Livepatch
The Real-time kernel is an Ubuntu kernel with PREEMPT_RT patches integrated.

This will change your kernel. To revert to your original kernel, you will need
to make the change manually.

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

You will now need to reboot your machine to complete the process. After rebooting, you will be running Real-time Ubuntu.

Install and enable manually#

To access the Real-time Ubuntu repository but not install the package immediately, you can use the --access-only flag, which was introduced in Pro Client version 27.11:

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

One moment, checking your subscription first
Real-time kernel cannot be enabled with Livepatch.
Disable Livepatch and proceed to enable Real-time kernel? (y/N) y
Disabling incompatible service: Livepatch
Updating Real-time kernel package lists
Skipping installing packages: ubuntu-realtime
Real-time kernel access enabled

Now that Real-time Ubuntu is accessible, you can install and enable it whenever you wish. For example, to install the generic Real-time kernel (not suitable for Raspberry Pi):

sudo apt install ubuntu-realtime

After rebooting, you’ll be running Real-time Ubuntu.

Next steps#

For more information about Real-time Ubuntu and how it can help you, refer to the official Real-time Ubuntu documentation.