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" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> 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 <[EMAIL PROTECTED]> 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. > > > > > > > _______________________________________________ > Asterisk-Users mailing list > [EMAIL PROTECTED] > http://lists.digium.com/mailman/listinfo/asterisk-users > To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-users > _______________________________________________ Asterisk-Users mailing list [EMAIL PROTECTED] http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
