Re: [cobalt-users] 99.9% up time

[Kris Dahl <krislists@xxxxxxxxxxxxx>]

on 4/12/00 10:27 PM, Jeff Lasman at jblists@xxxxxxxxxxxxx wrote:

> Colin Smith wrote:
> 
>>> I want to garanty a 99.9% up time to my customers.
>>> I have an idea on how to do it but I need some advise..
>>> I was thinking about imaging the rack once a day on another backup rack
>>> If anyone has done this before or has been doing it please let me know....
>>> Any information on garanting a 99.9% up time would be very apprechiatted.
>> 
>> 99.9% is 9 hours per year, that's easy. All you need for that is a good
>> UPS and a guaranteed network link. The box will do 99.9% all on it's own.
>> It's worth mirroring it's internal disks though just to be sure.
> 
> Surely you dream.
> 
> I had started to write an example of why not, but decided not to bother.

IMHO three nines is easy.  I could do that with crappy hardware and NT if I
was careful.  I don't think I have a single machine (even a workstation)
that isn't 99.9% available.  Start talking about 5 or 6 nines, and I start
getting impressed.

But if you want to guarantee 99.9%, you should invest in adequate power
protection, and keep near-line backups if at all possible.  Also co-locating
with a datacenter that provides the power and redundant connections with
full BGP routing to multiple carriers would be the easiest way to do it.
That way you aren't at the mercy of your ISP--cause its the weak link that
determines your availibility.

-k