On 3/13/26 7:11 PM, Ivan Dyukov via discuss wrote: > Hello, everyone! Hey!
> I’m running a setup with a large number of routes on the host. The issue is > that > OVS reloads all routes via netlink whenever the routing table changes. This > spikes > CPU usage to 100% and occasionally causes packet drops. Are you running FRR or some other BGP daemon on the host by any chance? Do you really need all those routes in your main routing table? The point is, in most cases it is possible to move most of the routes into a vrf or a different custom routing table, in which case, OVS should ignore those routes. At least that should be the case in versions released in the past few years. > > Could you please clarify the role of system routes in the OVS kernel datapath? They are not used for many things, but are used for some, e.g. reporting the tunnel next hops in the database, tunnel offload with TC, detection of the appropriate source IP for the sFlow traffic. Maybe something else. > I resolved the performance issue by disabling system route processing using > the > --disable-system-route option. However, I’d like to confirm: Is it safe to use > --disable-system-route with the kernel datapath in production, or could it > introduce functional issues or instability? This option is mostly for running unit tests and it's not documented and it's not used in production environments for that reason, so real world use cases are not tested with this option set. And, as mentioned above, using it breaks a few features. So, I'd not recommend using it in production in general. There are likely ways to isolate unwanted routes from OVS in some other ways, as it is likely that these routes don't really need to be in the main routing table in the first place, but it depends on the setup, of course. Best regards, Ilya Maximets. > > I have tested connectivity via Geneve tunnels with the system route feature > disabled, > and OVS continues to function correctly. What additional scenarios would you > recommend > testing to validate stability of the system? > > Best regards, > Ivan > > _______________________________________________ > discuss mailing list > [email protected] > https://mail.openvswitch.org/mailman/listinfo/ovs-discuss _______________________________________________ discuss mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-discuss
