To call it devastation if it erupted is an understatement
Only place you'd survive something like this, even if you were on the far side of the planet like I am, is a vault. The earth would be pitch black for at least ten years or more and no sunlight would reach the surface for growing. Safely belowground in an insulated dwelling with a source of heat would be the only possible strategy.
Microculture and sprouting would provide vital nutrition to people in your shelter during this period in addition to your food storage. Even the addition of anything green to your meals, no matter how nutritious they might be out of the can, would vastly improve morale. This is why it is important to learn how to use LEDs to create microgardens belowground.