On Thu, Mar 16, 2023 at 5:43 PM Danny Webb <Danny.Webb@thehutgroup.com> wrote:
Hi Kamil,
We're currently running 4 (soon to be 5) production regions all using kolla ansible as our deployer with OVN as our neutron backend. It's been fairly solid for us and we've had less issues with OVN than the traditional hybrid OVS / Iptables neutron driver (which we ran for about a year before switching to OVN). Our regions are anywhere from 50-60 compute hosts with 1-2k+ VMs per region. As far as I know most of the new development is going into OVN so would be a good place to start. Ultimately, we've only really had 2 real issues whilst running it. First was an issue where we had the provider network spamming gateway changes into southbound as we had our anycast SVI bound to our top of rack switches which made OVN keep updating it's location. We mitigated this by moving the provider SVIs to our border routers and the issue went away and dropped the load on our OVN controllers significantly. Only other real issue we had was during an upgrade of a region we ended up with what we believed to be some sort of stale flows that resulted in some hypervisors losing connectivity until we rebooted them.
Hope this helps!
Cheers,
Danny
From: Kamil Madac <kamil.madac@gmail.com>
Sent: 14 March 2023 09:46
To: openstack-discuss <openstack-discuss@lists.openstack.org>
Subject: [neutron]Hi All,
CAUTION: This email originates from outside THG
I'm in the process of planning a small public cloud based on OpenStack. I have quite experience with kolla-ansible deployments which use OVS networking and I have no issues with that. It works stable for my use cases (Vlan provider networks, DVR, tenant networks, floating IPs).
For that new deployment I'm looking at OVN deployment which from what I read should be more performant (faster build of instances) and with ability to cover more networking features in OVN instead of needing external software like iptables/dnsmasq.
Does anyone use OVN in production and what is your experience (pros/cons)?Is OVN mature enough to replace OVS in the production deployment (are there some basic features from OVS missing)?
Danny Webb Principal OpenStack Engineer Danny.Webb@thehutgroup.com 
