Be careful with rsync, whose original purpose is mirroring, not backups. Specifically, if you're using it as a backup system of any kind, you want to use the --delete-after option, or else your receiver might delete the file before the sender even finds out the hard disk is corrupt (--delete-before is default, which is dangerous for a backup system).

You may also want to set the --max-delete option, to avoid the scenario where the sender doesn't have the volume mounted, resulting in the receiver deleting everything.

Be also aware that rsync is completely unencrypted, so you need to use it in conjuction with sshfs, ecryptfs, or some other method if you want security.