Forum Moderators: phranque
There are 24hrs * 365days = 8760hrs in a (non-leap) year so...
99% uptime means over 87hrs downtime per year.
99.9% uptime means over 8hrs downtime per year.
Zero downtime is 'best' but realistically I require guaranteed/insured maximum 1-hr downtime per year (approx. 99.99% uptime). I find the premium for 100% uptime rarely cost effective. In practice that 99.99% is usually 100%. Which is nice.
Of course it depends on where a sites graphed cost of service and revenue rate lines cross. The less you make the greater tolerance you can afford.