If you use btrfs (nice for simple ad-hoc raid1 setups) then github.com/digint/btrbk is a very nice tool to automate snapshots and backups over ssh.

You can also improvise a setup with an external usb drive that you only connect once a week or so to do longer term backups. This isn’t exactly an off-site backup but somewhat similar if you store that drive away from the servers.