That's not too bad. But does that all add up to more than 9 hours a year of downtime? If so, you're already doing worse than 99.9% uptime. I would also bet you

That's not too bad. But does that all add up to more than 9 hours a year of downtime? If so, you're already doing worse than 99.9% uptime. I would also bet your uptime is worse than you think if you're not actively measuring it. However, I'm sure it is "good enough". I doubt it is worth spending an order of magnitude more money to get better than 3 9's for your business, which is more or less the point of the article imo. I find the percent availability -> hours of downtime chart on wikipedia to be a really helpful reference for these types of discussions: http://en.wikipedia.org/wiki/High_availability http://en.wikipedia.org/wiki/High_availability