How much time can a service be unavailable to meet a "five nines" uptime requirement?

How much time can a service be unavailable to meet a "five nines" uptime requirement?

• 5.3 minutes per year
• 87 hours per year
• 53 minutes per year
• 8.7 hours per year 

 

EXPLANATION

Five nines refers to a total operational potential of 99.999%. So for a 24x7 service, across a year that translates to less than 5.3 minutes of combined downtime.https://en.wikipedia.org/wiki/High_availability