Shane Reustle shared a detailed tutorial for how to “Clone Dropbox with a Raspberry Pi and BTSync“:
After constantly hitting my Dropbox space limit, I decided to build my own distributed backup tool. What I ended up with was an external hard drive with a dedicated Raspberry Pi that keeps in sync with my laptop over the internet using BitTorrent Sync. This new BTSync folder fully replaced my Dropbox folder, and allowed me to streamline my large media backups. I’ve explained every step of the build below.