Red Hat build of MicroShift

Automatically enable the MicroShift TuneD profile

Included in the microshift-low-latency RPM package is a systemd service that you can configure to automatically enable a TuneD profile when the system starts. This ability is particularly useful if you are installing MicroShift in a large fleet of devices.

Prerequisites

You installed the microshift-low-latency RPM package on the host.
You enabled low latency in the MicroShift config.yaml.
You created a TuneD profile.
You configured the microshift-baseline-variables.conf file.

Procedure

Configure the tuned.yaml in the /etc/microshift/ directory, for example:

Example tuned.yaml:

profile: microshift-baseline
reboot_after_apply: True

profile

Controls which TuneD profile is activated. In this example, the name of the profile is microshift-baseline.

reboot_after_apply

Controls whether the host must be rebooted after applying the profile. Valid values are True and False. For example, use the True setting to automatically restart the host after a new ostree commit is deployed.

The host is restarted when the microshift-tuned.service runs, but it does not restart the system when a new commit is deployed. You must restart the host to enable a new commit, then the system starts again when the microshift-tuned.service runs on that boot and detects changes to profiles and variables.

This double-boot can affect rollbacks. Ensure that you adjust the number of reboots in greenboot that are allowed before rollback when using automatic profile activation. For example, if 3 reboots are allowed before a rollback in greenboot, increase that number to 4. See the "Additional resources" list for more information.

Enable the microshift-tuned.service to run on each system start by entering the following command:

$ sudo systemctl enable microshift-tuned.service

If you set reboot_after_apply to True, ensure that a TuneD profile is active and that no other profiles have been activated outside of the MicroShift service. Otherwise, starting the microshift-tuned.service results in a host reboot.

Start the microshift-tuned.service by running the following command:

$ sudo systemctl start microshift-tuned.service

The microshift-tuned.service uses collected checksums to detect changes to selected TuneD profiles and variables. If there are no checksums on the disk, the service activates the TuneD profile and restarts the host. Expect a host restart when first starting the microshift-tuned.service.

Next steps

Optional: If you are using the x86_64 architecture, you can install Red Hat Enterprise Linux for Real Time (real-time kernel).