How to migrate from non-ha backend to non-ha backend + raft ha_backend

You might be re-using the storage backend since TLS information is stored on storage and not ha_storage. You will have to do a rolling update to prevent all nodes from the cluster being destroyed at the same time (or wipe out the storage backend’s data and start from scratch if that’s desired). If all cluster nodes are destroyed before a new one joins, then there’s not state to indicate that a cluster has already been bootstrapped.