does FTP even support his kind of thing?
You basically want to use an FTP server as a network drive, and 'backup' your huge data directly to the FTP, on the fly, without consuming space on your own machine? hrmm.
Do you know what the remote machine operating system is? do you have an account on it?
I would probably use rsync personally. Otherwise, is samba running on the remote server?
just providing options, not trying to have a dig.... It would be interesting if you could mount an FTP server's folder as a mountpoint/drive and 'work' off it like that! heh