On order to make backups of your server, we need root access via SSH. We need password access once, to add our public RSA key to your system. After that, we will use key based authentication, restricted to only use rsync.
To improve security, you could modify the sshd config and set:
Please mind, setting this can lock you out of your server if you have no other account to login!
Please do not remove our key from /root/.ssh/authorized_keys or remove this file, doing so will make it impossible for us to make backups!