Your math is off for four nines; 100% - 99.99% = 0.01%, which is just over 52 minutes per year. Also fun: https://en.wikipedia.org/wiki/High_availability#Perce

Your math is off for four nines; 100% - 99.99% = 0.01%, which is just over 52 minutes per year. Also fun: https://en.wikipedia.org/wiki/High_availability#Percentage_calculation https://en.wikipedia.org/wiki/High_availability#Percentage_c...