Service Control

Service control refers to the set of commands for enabling and disabling a given MicroOVN service. MicroOVN has a set of services referred to here Services Reference, which are responsible for handling core functionality.

You can disable services manually using snap, but the service control does not update the desired state or handle joining clusters and configuring the service properly, hence the strong reasoning to interact with services through this method.

Note

This assumes you have MicroOVN installed and a clustered across three of more nodes. These nodes will be referred to as first, second and third respectively.

Disabling a MicroOVN service

Disabling a MicroOVN service will configure it to not start automatically at boot and stop the service if it is running.

run on first:

microovn disable switch

Service switch disabled

To validate that this has worked, we can query the status of MicroOVN and check which services are enabled. We should find that all nodes have central, chassis and switch, except first having only central and chassis. This shows the disabling worked

run on first:

microovn status

MicroOVN deployment summary:
- first (10.190.155.5)
Services: central, chassis
- second (10.190.155.174)
Services: central, chassis, switch
- third (10.190.155.55)
Services: central, chassis, switch
OVN Database summary:
OVN Northbound: OK (7.3.0)
OVN Southbound: OK (20.33.0)

The other nodes have also been informed of this change to the service placement and when queried will confirm that switch is disabled on first from their perspective too.

run on second:

microovn status

MicroOVN deployment summary:
- first (10.190.155.5)
Services: central, chassis
- second (10.190.155.174)
Services: central, chassis, switch
- third (10.190.155.55)
Services: central, chassis, switch
OVN Database summary:
OVN Northbound: OK (7.3.0)
OVN Southbound: OK (20.33.0)

Enabling a MicroOVN service

Enabling a MicroOVN service will configure it to start automatically at boot and if the service is not running, start it.

run on first:

microovn enable switch

Service switch enabled

Note

If the switch service is enabled you may get an error, this is fine.

This will enable the switch service in MicroOVN, This can be shown through the listing of system services owned by MicroOVN. As mentioned in the disable section, these do not always translate directly to a MicroOVN service, but in this case it does.

run on first:

microovn status

MicroOVN deployment summary:
- first (10.190.155.5)
Services: central, chassis, switch
- second (10.190.155.174)
Services: central, chassis, switch
- third (10.190.155.55)
Services: central, chassis, switch
OVN Database summary:
OVN Northbound: OK (7.3.0)
OVN Southbound: OK (20.33.0)

You should be able to see here that the service is running and enabled on startup. The other nodes are also aware of this as if you query the status you will see it there and running.

run on second:

microovn status

MicroOVN deployment summary:
- first (10.190.155.5)
Services: central, chassis, switch
- second (10.190.155.174)
Services: central, chassis, switch
- third (10.190.155.55)
Services: central, chassis, switch
OVN Database summary:
OVN Northbound: OK (7.3.0)
OVN Southbound: OK (20.33.0)

Uses

Typically the most common use case of this will be to control the nodes the central services are running on and to increase the number of central services beyond the default of 3.