[Asterisk-Users] Hardware to build an Enterprise AsteriskUniversal Gateway

[Steve Totaro]

Automated failover is a nice thought in this instance but in the Telco world
it may not be necessary.  Most industries will allow for weekend work as
well as planned downtime (Yes, even in a three shift manufacturing facility)
In my experience, fires and acts of God are far and few between but someone
tripping over a power cord or shutting something down or pulling the wrong
patch cord is a regular occurance.  Not sure if I am agreeing with Steve or
not, the more I read his post the less I am sure what he is saying.

----- Original Message ----- 
From: "Steve Underwood" <steveu at coppice.org>
To: <asterisk-users at lists.digium.com>
Sent: Saturday, January 10, 2004 2:43 AM
Subject: Re: [Asterisk-Users] Hardware to build an Enterprise
AsteriskUniversal Gateway


> Hi,
>
> I don't want to drag this into a long thread, but note the original says
> "the system should survive just about anything short of an act of God",
> and suddenly you are talking about a reliable server and a few switches.
> These are quite different things. I have yet to see a 5 x 9's server
> room. Fire, mechanical damage and other factors will normally keep the
> location itself well below 5 x 9's. Think "system" instead of "server
> equipment", and the picture looks very different. Even for a single PC
> type server, downtime due to telecoms lines, power problems, fire,
> flood, typhoon damage, theft and a mass of other stuff mught well exceed
> the server unavailablility itself. I've seen many servers not fail in 5
> years. I have yet to see the best location go that long without causing
> at least one substantial period of downtime. 5 x 9's allows about 6
> minutes downtime a year. That means 100% of all failures must have
> automated failover, as manuals repair could never be achieved so fast.
> Physical diversity if essential for that.
>
> Regards,
> Steve
>
>
> Chris Albertson wrote:
>
> >--- Steve Underwood <steveu at coppice.org> wrote:
> >
> >
> >>WipeOut wrote:
> >>
> >>
> >>
> >>>Granted five 9's is never easy but in a cluster of 10+ servers the
> >>>system should survive just about anything short of an act of God..
> >>>
> >>>
> >>You do realise that is a real dumb statement, don't you? :-)
> >>
> >>A cluster of 10 machines, each on a different site. Guarantees from
> >>the
> >>power company - checked personally to see that aren't cheating - that
> >>
> >>you have genuinely independant feeds to these sites. Large UPSs, with
> >>
> >>diesel generator backups. Multiple diverse telecoms links between the
> >>
> >>
> >
> >If he says "cluster" he likely means 10 servers in one rack.  But still
> >you are right.  It is all the other stuff that could break.  You
> >will need paralleld Ethernet switches (Yes they make these, no, they
> >are NOT cheap.) you will need some kind of fail over.  The switches
> >can do that for you. (do a google on "level 3 switch")
> >
> >It's the level three switches that make .99999 possible but half or
> >more of your hardware will be just "hot spares" so it really will
> >take a rack full of boxes
> >
> >Each box should have mirrored drives and dual power supplies and each
> >AC power cord needs to go to it's own UPS
> >
> >Has anyone tried to build Asterisk on SPARC/Solaris?  One SPARC
> >server is almost five nines all by itself as it can do thinks
> >like "boot around" failed CPU, RAM or disks.  I've actually
> >pulled a disk drive out of a running Sun SPARC and applications
> >continoued to run.
> >
> >
>
>
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