RSSSLA 幾個9
1 月 21
https://technet.microsoft.com/en-us/library/cc748824.aspx#SolutionHA
Acceptable availability percentage
Downtime per day
Downtime per month
Downtime per year
90 (one nine)
144.00 minutes
72 hours
36.5days
99 (two nines)
14.40 minutes
7 hours
3.65 days
99.9 (three nines)
86.40 seconds
43 minutes
8.77 hours
99.99 (four nines)
8.64 seconds
4 minutes
52.60 minutes
99.999 (five nines)
0.86 seconds
26 seconds
5.26 minutes