How to enable Real-time kernel#


Real-time kernel is only supported on 22.04. For more information, please see

Enable and auto-install#


Once you enable Real-time kernel, enabling some Pro services will not be possible. For a better view of which services are compatible with Real-time kernel, please look at the services compatibility matrix

To enable 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 is introduced in 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 while enabling.

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

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

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.