so what is "5 nines"?

October 11, 2003

Thanks for visiting! Just a fair warning this post is fairly 'old' in tech terms and may contain outdated information and/or broken links or pictures. Please verify info and feel free to contact me if questions!

a recent isp issued caused me to remember just exactly what “uptime” means...here's a little taste:

guarantee % allowable downtime annually

99.9999 holy crap < 1 minute (six sigma)

99.999 5.2 minutes (famous "5 nines")

99.99 52.5 minutes

99.9 525.6 minutes (8.76 hours)

99 5256 minutes (87.6 hours)

if you are "lucky" to have a provider giving you a 90% guarantee, congrats, you could be down for an acceptable 36.5 days per year

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guarantee %	allowable downtime annually
99.9999	holy crap < 1 minute (six sigma)
99.999	5.2 minutes (famous "5 nines")
99.99	52.5 minutes
99.9	525.6 minutes (8.76 hours)
99	5256 minutes (87.6 hours)
if you are "lucky" to have a provider giving you a 90% guarantee, congrats, you could be down for an acceptable 36.5 days per year

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