In order to silence my every so slightly aging iMac I decided to swap the mechanical HD for a SSD. This also had the added benefit of increased speed, with one downside. A large reduction in storage capacity, I had gone from 1Tb down to 240Gb.
Around the same time I had upgraded my Dropbox to the Pro account, 1Tb of storage. I thought my storage problem would be solved. Oh wait, hang on, I still need the files locally to sync with Dropbox.
This problem set me down the path of configuring my Dropbox to sync files outside of the Dropbox folder. But instead of the folder being on an external drive (too noisy!), I would place the external folder on a Raspberry Pi with an external drive, placed in another room. No noise!
The following is a guide on how you can configure a Raspberry Pi with a Samba share, which in turn can be symbolically linked on OS X to a folder within Dropbox. Therefore, allowing you to have a large synchronised version of your Dropbox files locally.