You want to run a periodical and intelligent ftp backup.
A FTP backup isn’t for most a priority, but it’s definitely a necessity, so why not doing it in the best way possible?
The SiteVault incremental FTP backup functions this way: A first FTP backup is done and the information is transferred locally from the server.
The second time you backup only the modified or newly added files are downloaded and the filed from the previous backup that haven’t changed are moved to the current backup folder while recording that it did so, allowing you to restore the site as it was at a certain date.
This is fast and accurate taking the smallest possible time for your FTP backup.