According to https://docs.docker.com/engine/swarm/admin_guide/#/back-up-the-swarm-state backing up a docker swarm cluster is a simple as
cp -r /var/lib/docker/swarm/raft /tmp/backup && tar ... && scp ....
Does the backup process need to worry about online vs offline backups? Can I simply
cp -r or
rsync that folder without worrying about the integrity of the backup? Do I need to disable the swarm cluster to ensure an accurate backup? Finally, can I ensure that the swarm state is consistent at backup time?