On 07/11/2017 10:17 AM, Numan Siddique wrote:
Hello Tripleo team,
I have few questios regarding migration from neutron ML2OVS to OVN.
Below are some of the requirements
- We want to migrate an existing depoyment from Neutroon default
ML2OVS to OVN
- We are targetting this for tripleo Queen's release.
- The plan is to first upgrade the tripleo deployment from Pike to
Queens with no changes to neutron. i.e with neutron ML2OVS. Once the
upgrade is done, we want to migrate to OVN.
- The migration process will stop all the neutron agents, configure
neutron server to load OVN mechanism driver and start OVN services (with
no or very limited datapath downtime).
- The migration would be handled by an ansible script. We have a PoC
ansible script which can be found here [1]
And the questions are
- (A broad question) - What is the right way to migrate and switch the
neutron plugin ? Can the stack upgrade handle the migration as well ?
- The migration procedure should be part of tripleo ? or can it be a
standalone ansible script ? (I presume it should be former).
- If it should be part of the tripleo then what would be the command to
do it ? A update stack command with appropriate environment files for OVN ?
- In case the migration can be done as a standalone script, how to
handle later updates/upgrades since tripleo wouldn't be aware of the
migration ?
This last point seems like the crux of the discussion here. Sure, you
can do all kinds of things to your cloud using standalone bits, but if
any of them affect things tripleo manages (which this would) then you're
going to break on the next stack update.
If there are things about the migration that a stack-update can't
handle, then the migration process would need to be twofold: 1) Run the
standalone bits to do the migration 2) Update the tripleo configuration
to match the migrated config so stack-updates work.
This is obviously a complex and error-prone process, so I'd strongly
encourage doing it in a tripleo-native fashion instead if at all possible.
Request to provide your comments so that we can move in the right direction.
[1] - https://github.com/openstack/networking-ovn/tree/master/migration
Thanks
Numan
__________________________________________________________________________
OpenStack Development Mailing List (not for usage questions)
Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe
http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
__________________________________________________________________________
OpenStack Development Mailing List (not for usage questions)
Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe
http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
