Unless you are asleep at the wheel you must be picking up the buzz about the new BitTorrent sync program.
I now have my Android phone, syncing folders with with ubuntu desktop, syncing folders with my qnap nas (arm processor). All encrypted. Three chip sets, one Linux platform, how cool is that? It even does Windows machines!
If you were asleep, simply download the binaries from the android and qnap app stores, or the Bittorrent website. Fire up each machine. Choose a folder on each one to sync (usually one full to sync to a new empty one). Generate a key/string and copy it to the other machine. That's it. On the same Lan that's instant, and over the Wan, Bittorrent servers help share the keys. Okay that last bit appears to be a potential security hole, but Bittorrent are apparently reviewing whether to go the open source route.
This one program has solved all my backup/sync problems in one fell swoop. I haven't used google drive or dropbox in over a week now.