[ovs-dev] [RFC] Make openvswitch start before networking.

[Gurucharan Shetty]

>> > What about when the controller is on network? You have to have that up
>> > (networking-wise) before bring up the bridge, right?
>> Can you elaborate with an example?
>>
>> I don't know of a use case yet where the controller wants to control a
>> OVS bridge that is also responsible for SSH (or network connections)
>> to the machine (Is there any?). If OVS starts before networking, it
>> can be setup (e.g: through 'interfaces') to have all other bridges in
>> secure mode and they will keep retrying till they get controller
>> connection.
>
> Isn't that the most common use-case? You have a host with ovs bridge
> that needs networking up & running to be able to connect to the
> controller.  If you start OVS before that, then it will fail and
> the switch creates flows as needed.
>
> It's possible to use secure mode, but the admin has to consider the
> initialization order to remember to use that option.  Maybe secure
> mode should be assumed when a controller is configured into the bridge.
Yes. Otherwise, if you loose connectivity to the controller (assume a
transient network failure), you will start acting like a mac learning
bridge anyways.

>
>> What if we remove openvswitch dependency to NFS and expect the users
>> that have /usr on NFS to mount it through initramfs. Then we can start
>> openvswitch before networking.
>
> I see no other problem besides the controller issue above.
>
> fbl