I have a RB4011iGS+RM that I want to install the Dude server on. Specs show the RB4011iGS+RM has 512MB of NAND storage but doesn't mention any external hard drive interface. Is it recommended to install Dude on NAND storage, or should I be using an external HDD? It doesn't seem like the RB4011iGS+RM provides any way to attach additional storage. What do you recommend?