Could you live off peanut butter and water for extended period?

So peanut butter is good for years and when it does go bad its still edible- the taste just changes right? So if you had a water source and giant barrels of peanut butter how long could you survive? Months, years, forever? I realize you'd be missing vitamins and such but the question is just how long could you survive? (Its cheap and easy to store so hypothetically you could have tubs or barrels of it for survival situations if it was enough to keep you going.)