but think of the alternative: graphics consoles everywhere? kvm switches
everywhere? even an old pc with a cyclades card is about the cost of a
kvm switch with a comparable number of ports. the serial consoles can be
logged, you can get to a console from anywhere on the 'ent if you like,
and so on. think of the cost for an operator to keep on plugging monitors
and keyboards in to 1800 machines as needed, versus a one time cost of
probably 10-20 kilobux or so to wire the lot of them up to centralized
serial consoles.
at Pitt, where i did my undergrad, all the machines (only about 300,
admittedly) had their serial consoles tied in to a (!) vaxstation 
running some software to easily manage the consoles of hundreds of 
machines, log them, etc.. they had a second vaxstation clustered with it 
and those two machines sat in the operator's booth/hangout area/holding 
bay. terminal servers are pretty cheap on the used market, and make light
work of all this. you can put a terminal server in the same rack and on the
same ethernet... plus with serial consoles, the console traffic is data, 
machine readable.. a script that's tailing a log of a console session can 
notice that, say, a machine has panicked or the kernel wrote something out
(which in the case of some problem with syslog would never get logged.. 
i'd expect with 1800 machines that the syslogs talk over the network to 
more centralized loggers?) , it can page you or send someone mail or 
alert the world that theres a problem... etc etc etc.. i'd say it is way 
nicer to have serial consoles, and then have those hooked into a terminal 
server or something where a machine can keep an eye on it for me. the modern
buzzword 'autonomic computing' , which is just a rehash of several 
previous generations of buzzwords, can be had for real with a bit of work 
on the part of the sysadmin (as opposed to a mountain of work on the part 
of a vendor, who will never wuite get the picture anyway)

just my 0.02,
isildur

On Tue, 22 Oct 2002, Jorgen Lundman wrote:

> 
> Me too! It's a sloppy network we have, alright. We have 1800 cobalt 
> servers, which means each rack has to have 2 switches, and each row of 
> racks have a router at the end for all the switches, just for the 
> network cabling. To do all of those to have serial as well would have a 
> cost associated with it I don't think management wants to spring for. Oh 
> well :)
> 
> I do feel a bit for the original patcher of this thread, who thought it 
> be nice to offer his diffs, told to do something more "proper" then shot 
> down because it's bloat. Not complaining or putting blame on anyone, it 
> just puts people off contributing, I know it did for me.
> 
> Take care,
> 
> Lundy
> 
> 
> matthew green wrote:
> >    
> >    Frankly, if you don't have console's on your servers, then they can't
> >    be all that important and then it just doesn't matter when you turn
> >    them off.
> >    
> >    Sysadmins build machinerooms with consoles, console cables, and 
> >    console servers.  I have a machineroom with close to 200 machines
> >    in it, and I have one monitor.  I can get to any console on those
> >    machines from anywhere, even across the planet.
> >    
> >    If you want to build a hacked up network, then that's up to you. But
> >    then you can hack up your kernel with whatever code you want too. But
> >    don't make everyone else have to have that code there just because
> >    you like to run a sloppy network.
> > 
> > 
> > 
> > i wish i had the hardware to do this.  send me a few supported
> > multiport serial cards?  i just don't have the supported hardware
> > to have all my machines with serial console connected at the
> > same time, and this feature would be useful for the couple that
> > do not have soft power (ie, halt -p doesn't work.)
> > 
> > 
> > .mrg.
> > 
> > 
> 
> -- 
> Jorgen Lundman       | <lundman@lundman.net>
> Unix Administrator   | +81 (0)3 -5456-2687 ext 1017 (work)
> Shibuya-ku, Tokyo    | +81 (0)90-5578-8500          (cell)
> Japan                | +81 (0)3 -3375-1767          (home)
> 
>