openstack
/
neutron
Code Issues Proposed changes
neutron/tools/ovn_migration
History
yatinkarel 435c869f1a ovn migration: Fix check for stack name 
[1] Updated the migration script to check for config-download
directory instead of stack, but missed update the Error
message.

check_stack function is renamed to check_source_inventory
as now it only checks for source inventory instead of heat
stack.
If source inventory file doesn't exist the script
will report Error message and exit.

This is follow up of [1].

[1] https://review.opendev.org/c/openstack/neutron/+/834925

Related-Bug: #1966099
Change-Id: I2416fba50fc495da4d59a3f335f33d831ca6e91d
(cherry picked from commit ccf8e71efa)
 		2022-04-25 04:49:18 +00:00
..
infrared/tripleo-ovn-migration Replace cirros 0.4.0 by 0.5.2 in ovn migration create-resources.sh.j2 2021-09-28 14:44:09 +00:00
tripleo_environment ovn migration: Fix check for stack name 2022-04-25 04:49:18 +00:00
README.rst Migrate the OVN migration scripts 2020-03-31 15:35:35 +01:00
hosts.sample Migrate the OVN migration scripts 2020-03-31 15:35:35 +01:00
migrate-to-ovn.yml Migrate the OVN migration scripts 2020-03-31 15:35:35 +01:00

README.rst

Migration from ML2/OVS to ML2/OVN

Proof-of-concept ansible script for migrating an OpenStack deployment that uses ML2/OVS to OVN.

If you have a tripleo ML2/OVS deployment then please see the folder tripleo_environment

Prerequisites:

  1. Ansible 2.2 or greater.
  2. ML2/OVS must be using the OVS firewall driver.

To use:

  1. Create an ansible inventory with the expected set of groups and variables as indicated by the hosts-sample file.

  2. Run the playbook:

    $ ansible-playbook migrate-to-ovn.yml -i hosts

Testing Status:

  • Tested on an RDO cloud on CentOS 7.3 based on Ocata.
  • The cloud had 3 controller nodes and 6 compute nodes.
  • Observed network downtime was 10 seconds.
  • The "--forks 10" option was used with ansible-playbook to ensure that commands could be run across the entire environment in parallel.

MTU:

  • If migrating an ML2/OVS deployment using VXLAN tenant networks to an OVN deployment using Geneve for tenant networks, we have an unresolved issue around MTU. The VXLAN overhead is 30 bytes. OVN with Geneve has an overhead of 38 bytes. We need the tenant networks MTU adjusted for OVN and then we need all VMs to receive the updated MTU value through DHCP before the migration can take place. For testing purposes, we've just hacked the Neutron code to indicate that the VXLAN overhead was 38 bytes instead of 30, bypassing the issue at migration time.