Here is a great example of the back side (view) of a big bun updo to help you with your styling or to be able to show your hairdresser what you want.
Lots of bobby pins help to hold the pieces in place. Unwashed hair works best as it stays in place better for an updo. A ponytail is placed at the top of the crown and the strands are puffed up and under and secured. She has long blonde hair with which to make this style happen. Here is a picture of the front of her style as well.
She is wearing a black and white and red dress here at The American Red Cross Red Tie Affair 2011.