The board it's running on only has three SATA ports, of which one is an mSATA connection. It currently has a motley collection of a 64GB Crucial M4 mSATA, a 250GB Crucial M500, and a 128GB Samsung ...
I've been using Proxmox a lot recently, deploying various different systems and containers across both of my machines in order to move some of my more essential systems away from my main server.