If we are using an operating system with the systemd init system, we can easily use the systemctl command to start, stop, or check the status of any OpenStack daemons running on a particular server.
For example, to check the status of the nova-api service, we can run the following command:
$ sudo systemctl status nova-api
We should see output similar to Figure 10.5.
Figure 10.5: Output from the systemctl status command
This shows us that the nova-api service is currently running and will be started on reboot (enabled). If the service was stopped, we could easily start it back up by running the following:
$ sudo systemctl start nova-api
If we want to restart a service, we can run the following:
$ sudo systemctl restart nova-api
The exam does not require you to edit any specific OpenStack configuration files—but a good rule of thumb for live OpenStack...
