System Reliability

As they say, if you haven't seen it before, it's new to you. So today I learned something amazing, shocking (it was shocking to me), and completely mundane for those who deal with providing services day in and day out. System Reliability, which is relate to the system up time, is defined in terms of 9's: 99%, 99.9%, 99.99%, etc. Seems like splitting hair, at first. Big deal, whether it's 99% or 99.99%. Well, it does. For a system running 24/7, 99% uptime implies 88 hours of downtime per year, while 99.99% implies 53 minutes a year. Big efen difference!