Advice on getting a computer lab server

[David Trask]

Ian,

A faster server will definitely help, but the first problem is the 10/100
switch and perhaps the NIC coming from the server.  Back in the old days,
(I've been running linux terminals in my school since 2001) I used to have
this issue....with Tuxtyping and so forth.  One day I tried an
experiment...I switched to gigabit.  I already had a gigabit NIC in the
server, but it was connected to a 100 baseT port.  I simply got a switch
with a gigabit uplink port and WOW!  Suddenly, everyone could play
Tuxtyping!  

It's like this.  Imagine you have 20 kids in a room.  When the bell rings
they are going to exit the room and go out into the hall and then each go
into 20 different classrooms individually.  They will exit via a normal
size door and enter the other classrooms by normal sized doors.  The issue
becomes, in this case, how quickly they can exit the first room. 
NOW...take the same scenario except in the originating room...now you have
a large door the size of a garage or barn door.  Same kids....same
destination...except now they can leave the originating room MUCH faster. 
This is the analogy of what is happening at the server.  The bottleneck
right now is at the server...by switching to gigabit coming out of the
server (gigabit NIC and gigabit switch) you now shift the bottleneck down
to the client...where it belongs.

I hope this helps!  I too run Starfall reading and a host of other
Flash-based sites in my lab.  We are able to do so without any issues  :-)

Ian Mackenzie <ianmackenz at gmail.com> writes:
>Joe wrote:
>
>Here's a few final questions if you don't mind.
>
>In my current lab if I try to run more than about 7 thin clients they
>freeze up just playing flash games or running tuxtyping. Like I said, I
>have 4GB of Dual Channel DDR RAM so is the bottleneck with my 10/100
>switch or my P4 CPU? Until now I've thought it was the CPU because when I
>look at the system monitor the CPU maxes out pretty quick. (maybe I
>should bring my c2d in from home and try it out to see how it holds up) 
>
>If I want to use the above programs and keep my current curriculum will a
>single server with 2 dual core xeons and 8 GB RAM be fast or just
>adequate? I want the lab to be fast. (obviously I'm just asking your
>opinion here) 
>
>Finally, what kind of switch should I get? Should I go all gigabit or is
>it enough to just be gigabit to the server and 10/100 to the clients? I
>do a lot of flash based reading games and stuff with the lower grades
>like [ http://starfall.com ]starfall.com and so I absolutely must have
>these activities perform well.
>
>--------------
>
>    
>
>(From the Edubuntu web site) “If you have more than 10 users, it is
>recommended to use gigabit ethernet for your LTSP servers. Although
>normal usage ranges from 0.5 to 2mbit, clients can peak quite high
>(70mbit), especially when watching multimedia content. “
>
>
>
>So, gigabit from server -> switch and 100M from switch to client PCs
>sounds about right. I"m about to build a core2Quad to serve the computer
>lab, and see how it runs, and if there is room for expansion.
>
>Ian Mackenzie
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David N. Trask
Technology Teacher/Director
Vassalboro Community School
dtrask at vcsvikings.org
(207)923-3100