On Wed, Jan 1, 2025 at 10:17 PM Satish Patel <satish.txt@gmail.com> wrote:

Folks,

I have OVN running on 3 node controllers with a RAFT clustering. What is the best way to take backup of all the databases of nb_db and sb_db and how to restore them during a full disaster situation? 

Is the following the correct way to take backup? 

ovsdb-client backup unix:///run/ovn/ovnnb_db.sock OVN_Northbound > nb-snap-$(date +%s).txt

ovsdb-client backup unix:///run/ovn/ovnsb_db.sock OVN_Southbound > sb-snap-$(date +%s).txt

That is what we do when migrating OVN data from RHOSP 17 to RHOSO 18 (Red Hat distro): https://openstack-k8s-operators.github.io/data-plane-adoption/user/index.html#migrating-ovn-data_migrating-databases We also update to new schema but you probably don't need that for simple backup.

 

During restore on what node we should restore and does restore work on fresh cluster or existing cluster? 

I believe you will have to rebuild your RAFT cluster. Start with one node, restore data there, then join cluster for more nodes. You may find some useful instructions in upstream docs for ovs raft implementation: https://docs.openvswitch.org/en/latest/ref/ovsdb.7/#manual-cluster-recovery

 

How do other folks handle disaster scenarios where all 3 nodes are down or required migration?