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Re: [openstack-dev] [ovs-discuss] OpenStack and OVN integration is failing on multi-node physical machines.(probably a bug)

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Hi Pranab,

Request to not drop the mailing list

Please see below for comments.

On Sat, May 27, 2017 at 11:30 AM, pranab boruah <


Thanks Numan for the reply. I modified the system service script of
neutron server and made sure that it starts only after ovn-northd service
is up and running.

Able to launch VMs now.
But the VMs doesn't get any dhcp ip. Is there any logs relevant to ovn
native dhcp server that I can look for?

Since you are using Newton, you probably need to set ovnnativedhcp=True
in /etc/neutron/plugin.ini or /etc/neutron/plugins/ml2/ml2_conf.ini.
Otherwise you are expected to use dhcp agent.

I have another question:
There are two ways to include the OVN specific configurations. One way is
to add a new [ovn] section in /etc/neutron/plugin.ini file. Second way is
to modify the /etc/neutron/plugins/networking-ovn/networking-ovn.ini
file. Which is the right file that we should modify and if I had included
the ovn configurations in both files, which one takes precedence?

Better to use etc/neutron/plugin.ini or
/etc/neutron/plugins/ml2/ml2_conf.ini. I think the last included config
file overrides the values.

After all this issues with the setup, we are planning to build a Triple-O
setup. I remember Russell Bryant mentioning that there is a Heat template
for OVN. We are planning to use that. Any caveats/guides you would like to
recommend for triple-O OVN integration? It would be really useful.

You need to include
[1] in the environment templates when calling openstack overcloud deploy
and it should work.
I would suggest using Ocata or master and OVS 2.7 in order to have a
successful deployment.
You can virt-customize your overcloud image and update ovs if you like.
There is a small script here [2] which does that. You can have a look into
it if you want.


[1] -

[2] -


On May 24, 2017 23:38, "Numan Siddique" wrote:

On Tue, May 23, 2017 at 6:48 PM, pranab boruah <> wrote:

We are building a multi-node physical set-up of OpenStack Newton. The
goal is to finally integrate the set-up with OVN.
Lab details:
1 Controller, 2 computes

CentOS-7.3, OpenStack Newton, separate network for mgmt and tunnel
OVS version: 2.6.1

I followed the following guide to deploy OpenStack Newton using the
PackStack utility:

Before I started integrating with OVN, I made sure that the set-up(ML2
and OVS) was working by launching VMs. VMs on cross compute node were
able to ping each other.

Now, I followed the official guide for OVN integration:

Error details :
Neutron Server log shows :

ERROR networkingovn.ovsdb.implidlovn [-] OVS database connection
to OVN
Northbound failed with error: '{u'error': u'unknown database',
u'details': u'getschema request specifies unknown database
Northbound', u'syntax': u'["OVNNorthbound"]'}'. Verify that the
OVS and OVN services are available and that the 'ovn
and 'ovn
sb_connection' configuration options are correct.

The issue is ovsdb-server on the controller binds with the port
6641.instead of 6640.

Hi Pranab,
Normally I have seen this happening when neutron-server (i.e the
networking-ovn ML2 driver) tries to connect to the OVN northbound
ovsdb-server (on port 6641) and fails (mainly because the OVN NB db
ovsdb-server) is not running. In such case the code here [1] runs
"ovs-vsctl add-connection ptcp:6640:.. which causes the main ovsdb-server
(for conf.db) to listen on port 6641.

Can you make sure that ovsdb-server's for OVN are running before the
neutron-server is started.

May be to see if it works you can run "ovs-vsctl del-manager" and then run
netsat -putna | grep 6641 and verify that OVN NB db ovsdb-server listens on

[1] -


netstat -putna | grep 6641

tcp 0 0*
LISTEN 809/ovsdb-server

netstat -putna | grep 6640 (shows no output)

Now, OVN NB DB tries to listen on port 6641, but since it is used by
the ovsdb-server, it's unable to. PID of ovsdb-server is 809, while
the pid of OVN NB DB is 4217.

OVN NB DB logs shows this:

listen failed: Address already in use
2017-05-23T12:58:11.946Z|01422|socketutil|ERR|6641: bind:
Address already in use
util|ERR|6641: bind:
Address already in use

Solutions I tried:
1) Completely fresh installing everything.
2) Tried with OVS 2.6.0 and 2.7, same issue on all.
3) Checked and verified : SB and NB configuration options in
plugin.ini are exactly correct.

Please help. Let me know. if additional details are required.


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asked May 31, 2017 in openstack-dev by nusiddiq_at_redhat.c (820 points)   1