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RE: availability and resiliency

  • From: Leo Nelson
  • Date: Fri Sep 29 13:29:11 2000

Title: RE: availability and resiliency
Thank all of you who responded. I appreciate it.
-----Original Message-----
From: Chris Flores []
Sent: Friday, September 29, 2000 10:20 AM
To: 'Leo Nelson'; ''; Andrew Bangs
Subject: RE: availability and resiliency

Leo -
The '9' refers to a specific SLA (service level agreement). 5 9's is the guaranteed amount of network uptime. Another way to state 5 9's is - 99.999% uptime. This of course yields the amount of time a customer's service is not available. 5 9's is equivalent to 315 un-available seconds per year or 5 minutes.
Best regards.
-----Original Message-----
From: Leo Nelson []
Sent: Friday, September 29, 2000 12:08 PM
To: ''; Andrew Bangs
Subject: RE: availability and resiliency

Pardon my ignorance, but what the heck does a "9" refer too? Is it a UPS, rack, floor space, circuit...

Thanks in advance

-----Original Message-----
From: Lionel Lauer []
Sent: Friday, September 29, 2000 10:54 AM
To: Andrew Bangs
Subject: Re: availability and resiliency

On Fri, 29 Sep 2000 17:39:04 +0100, Andrew Bangs <>

>On Thu, Sep 28, 2000 at 02:39:40PM -0600, Irwin Lazar wrote:
>> Hi all,
>> Does anyone know if a template exists for what it takes to provide 5 9's of
>> availability, 4 9's etc.for Internet data centers?  Specifically I'm looking
>> for something that would say "if you want 5 9's of availability, here's what
>> you need to do", and so on.
>For 5 9s you need:
>1) Lots of money
>2) Lots of clue
>3) Lots of luck
>4) Lots of balls
>You can do 4 9s with any 3 of the above.

Too true.

But you forgot to include 'halfway-clued management' - without that you
haven't got a hope in hell of even getting three 9's. ;)

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