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

[Steve Underwood]

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. 
>  
>