LXB Removal and OVN migration
Hello openstack-discuss, With the removal of the linuxbridge mechanism driver, has anyone successfully completed an in-place migrationfrom LinuxBridge to OVN? I did come across this https://www.jimmdenton.com/migrating-lxb-to-ovn/ and that looks good as a one-shoit while biting the bullet and taking a full outage. However, I was wondering if it was possible to run lxb and ovn side-by-side and cut them over, say one network at a time. This particular deployment was stood up using openstack-ansible back in the rocky days (now running antelope) and it appears that openstack ansible's default was lxb up until Zed. Any suggestions or recommendations on the best path forward? Also, will the dynamic routing agent work with ovn?
Hi, There's a group of operators share there results and views on the migration from the Linuxbridge driver, check this thread for details: https://lists.openstack.org/archives/list/openstack-discuss@lists.openstack.... For dynamic-routing agent I suppose you reference the neutron-dynamic-routing project. n-d-r is tested with OVN backend in the last cycles (perhaps since 2023.1 Antelope release), so it should be fine for you to integrate it with OVN. Best wishes Lajos Katona (lajoskatona) Ricardo Cano <ledsole@gmail.com> ezt írta (időpont: 2025. márc. 3., H, 18:04):
Hello openstack-discuss,
With the removal of the linuxbridge mechanism driver, has anyone successfully completed an in-place migrationfrom LinuxBridge to OVN? I did come across this https://www.jimmdenton.com/migrating-lxb-to-ovn/ and that looks good as a one-shoit while biting the bullet and taking a full outage. However, I was wondering if it was possible to run lxb and ovn side-by-side and cut them over, say one network at a time.
This particular deployment was stood up using openstack-ansible back in the rocky days (now running antelope) and it appears that openstack ansible's default was lxb up until Zed.
Any suggestions or recommendations on the best path forward?
Also, will the dynamic routing agent work with ovn?
Hi Ricardo, We're in the same situation (Openstack-Ansible installed cloud) that's been in production for many years using Linuxbridge and a combination of VLAN and VXLAN networks running Openstack 2024.1 with the VMs using a mix of Ceph and local storage. We planned to upgrade to 2025.1, but the removal of the Linuxbridge mechanism driver complicates things massively. The CERN blog series (https://techblog.web.cern.ch/techblog/post/linuxbridge-ovn-migration-part-3/) and https://www.jimmdenton.com/migrating-lxb-to-ovn/ are useful as a starting point, but they are either too site specific (e.g. CERN's mega cells) or too lab-like environments, so I was hoping to hear from somebody who actually did this in a more "standard" Openstack deployment. We can shutdown the instances and take everything down for a weekend, but it doesn't seem to be a risk free way of doing the upgrade. Thanks a lot for any insight you or anyone else can provide. Thanks, George
hi George here goes my take on migrating (not linuxbridge, but ovs) to OVN, that you may take some "inspiration" https://github.com/mariojmdavid/migrate-to-ovn best Mario On 11/7/25 14:41, lmihaiescu@gmail.com wrote:
Hi Ricardo,
We're in the same situation (Openstack-Ansible installed cloud) that's been in production for many years using Linuxbridge and a combination of VLAN and VXLAN networks running Openstack 2024.1 with the VMs using a mix of Ceph and local storage.
We planned to upgrade to 2025.1, but the removal of the Linuxbridge mechanism driver complicates things massively. The CERN blog series (https://techblog.web.cern.ch/techblog/post/linuxbridge-ovn-migration-part-3/) and https://www.jimmdenton.com/migrating-lxb-to-ovn/ are useful as a starting point, but they are either too site specific (e.g. CERN's mega cells) or too lab-like environments, so I was hoping to hear from somebody who actually did this in a more "standard" Openstack deployment.
We can shutdown the instances and take everything down for a weekend, but it doesn't seem to be a risk free way of doing the upgrade.
Thanks a lot for any insight you or anyone else can provide.
Thanks, George
participants (4)
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Lajos Katona
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lmihaiescu＠gmail.com
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Mario David
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Ricardo Cano