I don’t do a full system backup, just data I need. I use restic to backup to B2 storage. As for docker data and databases I have a script that brings down the containers, runs a sqldump (or db type equivalent) into a tar.bz file and that gets backed up before bringing the containers back up. I used to run a Borg backup to a local drive and then rclone that to B2 so I have live data, local data, and remote. But these days I just back up remote and suck up the egress costs if needed.