ubuntu@juju-6a9998-zaza-27137d07dbef-1:~$ sudo systemctl restart openvswitch-switch

ubuntu@juju-6a9998-zaza-27137d07dbef-1:~$ systemctl status ovn-host                                                                                                                                                                                               
● ovn-host.service - LSB: OVN host components
   Loaded: loaded (/etc/init.d/ovn-host; generated)
   Active: active (running) since Thu 2021-01-28 23:56:33 UTC; 14s ago
     Docs: man:systemd-sysv-generator(8)
    Tasks: 5 (limit: 2361)
   CGroup: /system.slice/ovn-host.service
           ├─27400 ovn-controller: monitoring pid 27401 (healthy)
           └─27401 ovn-controller unix:/var/run/openvswitch/db.sock -vconsole:emer -vsyslog:err -vfile:info --no-chdir --log-file=/var/log/openvswitch/ovn-controller.log --pidfile=/var/run/openvswitch/ovn-controller.pid --detach --monitor

Jan 28 23:56:33 juju-6a9998-zaza-27137d07dbef-1 systemd[1]: Starting LSB: OVN host components...
Jan 28 23:56:33 juju-6a9998-zaza-27137d07dbef-1 ovn-host[27374]:  * Starting ovn-controller
Jan 28 23:56:33 juju-6a9998-zaza-27137d07dbef-1 systemd[1]: Started LSB: OVN host components.

ubuntu@juju-6a9998-zaza-27137d07dbef-1:~$ sudo systemctl stop ovn-host       
                                                                                                                                                                                                     
ubuntu@juju-6a9998-zaza-27137d07dbef-1:~$ systemctl status ovn-host                                                                                                                                                                                                            
● ovn-host.service - LSB: OVN host components
   Loaded: loaded (/etc/init.d/ovn-host; generated)
   Active: inactive (dead) since Thu 2021-01-28 23:56:53 UTC; 3s ago
     Docs: man:systemd-sysv-generator(8)
  Process: 27965 ExecStop=/etc/init.d/ovn-host stop (code=exited, status=0/SUCCESS)
    Tasks: 5 (limit: 2361)
   CGroup: /system.slice/ovn-host.service
           ├─27400 ovn-controller: monitoring pid 27401 (healthy)
           └─27401 ovn-controller unix:/var/run/openvswitch/db.sock -vconsole:emer -vsyslog:err -vfile:info --no-chdir --log-file=/var/log/openvswitch/ovn-controller.log --pidfile=/var/run/openvswitch/ovn-controller.pid --detach --monitor

Jan 28 23:56:33 juju-6a9998-zaza-27137d07dbef-1 systemd[1]: Starting LSB: OVN host components...
Jan 28 23:56:33 juju-6a9998-zaza-27137d07dbef-1 ovn-host[27374]:  * Starting ovn-controller
Jan 28 23:56:33 juju-6a9998-zaza-27137d07dbef-1 systemd[1]: Started LSB: OVN host components.
Jan 28 23:56:52 juju-6a9998-zaza-27137d07dbef-1 systemd[1]: Stopping LSB: OVN host components...
Jan 28 23:56:53 juju-6a9998-zaza-27137d07dbef-1 ovn-host[27965]:  * ovn-controller is not running
Jan 28 23:56:53 juju-6a9998-zaza-27137d07dbef-1 systemd[1]: Stopped LSB: OVN host components.

ubuntu@juju-6a9998-zaza-27137d07dbef-1:~$ sudo systemctl start ovn-host        
                                                                                                                                                                                                   
ubuntu@juju-6a9998-zaza-27137d07dbef-1:~$ systemctl status ovn-host                                                                                                                                                                                                           
● ovn-host.service - LSB: OVN host components
   Loaded: loaded (/etc/init.d/ovn-host; generated)
   Active: active (running) since Thu 2021-01-28 23:57:11 UTC; 1s ago
     Docs: man:systemd-sysv-generator(8)
  Process: 27965 ExecStop=/etc/init.d/ovn-host stop (code=exited, status=0/SUCCESS)
  Process: 27995 ExecStart=/etc/init.d/ovn-host start (code=exited, status=0/SUCCESS)
    Tasks: 10 (limit: 2361)
   CGroup: /system.slice/ovn-host.service
           ├─27400 ovn-controller: monitoring pid 27401 (healthy)
           ├─27401 ovn-controller unix:/var/run/openvswitch/db.sock -vconsole:emer -vsyslog:err -vfile:info --no-chdir --log-file=/var/log/openvswitch/ovn-controller.log --pidfile=/var/run/openvswitch/ovn-controller.pid --detach --monitor
           ├─28011 ovn-controller: monitoring pid 28012 (healthy)
           └─28012 ovn-controller unix:/var/run/openvswitch/db.sock -vconsole:emer -vsyslog:err -vfile:info --no-chdir --log-file=/var/log/openvswitch/ovn-controller.log --pidfile=/var/run/openvswitch/ovn-controller.pid --detach --monitor

Jan 28 23:57:11 juju-6a9998-zaza-27137d07dbef-1 systemd[1]: Starting LSB: OVN host components...
Jan 28 23:57:11 juju-6a9998-zaza-27137d07dbef-1 ovn-host[27995]:  * Starting ovn-controller
Jan 28 23:57:11 juju-6a9998-zaza-27137d07dbef-1 systemd[1]: Started LSB: OVN host components.

ubuntu@juju-6a9998-zaza-27137d07dbef-1:~$ sudo systemctl stop ovn-host

ubuntu@juju-6a9998-zaza-27137d07dbef-1:~$ systemctl status ovn-host
● ovn-host.service - LSB: OVN host components
   Loaded: loaded (/etc/init.d/ovn-host; generated)
   Active: inactive (dead) since Fri 2021-01-29 00:02:41 UTC; 1s ago
     Docs: man:systemd-sysv-generator(8)
  Process: 28618 ExecStop=/etc/init.d/ovn-host stop (code=exited, status=0/SUCCESS)
    Tasks: 5 (limit: 2361)
   CGroup: /system.slice/ovn-host.service
           ├─27400 ovn-controller: monitoring pid 27401 (healthy)
           └─27401 ovn-controller unix:/var/run/openvswitch/db.sock -vconsole:emer -vsyslog:err -vfile:info --no-chdir --log-file=/var/log/openvswitch/ovn-controller.log --pidfile=/var/run/openvswitch/ovn-controller.pid --detach --monitor

Jan 28 23:57:11 juju-6a9998-zaza-27137d07dbef-1 systemd[1]: Starting LSB: OVN host components...
Jan 28 23:57:11 juju-6a9998-zaza-27137d07dbef-1 ovn-host[27995]:  * Starting ovn-controller
Jan 28 23:57:11 juju-6a9998-zaza-27137d07dbef-1 systemd[1]: Started LSB: OVN host components.
Jan 29 00:02:41 juju-6a9998-zaza-27137d07dbef-1 systemd[1]: Stopping LSB: OVN host components...
Jan 29 00:02:41 juju-6a9998-zaza-27137d07dbef-1 ovn-host[28618]:  * Exiting ovn-controller (28012)
Jan 29 00:02:41 juju-6a9998-zaza-27137d07dbef-1 systemd[1]: Stopped LSB: OVN host components.