[K12OSN] Re: Server sizing in the real world

[William Fragakis]

Computer labs and classrooms, imho, need different server specs. What 
we've found in our lab is that it's the one place where 25 kids hit the 
same flash-enabled web site at exactly the same time. A single flash 
animation can drain 10-15% of the cpu on our dual core 2.8 ghz P4 
server (2gb) ram. We can put 10 on a server fine but I wouldn't want to 
push it much above that. I've seen some pop-up animations drain 50% or 
more of the server. All you need is a couple of those to keep your 
server from responding quickly to other requests. And, our lab is our 
showcase, we didn't want the servers to even hint at lagging since 
K12LTSP was replacing a room full of Win XP Celeron 1.8s.

If the lab is just for occasional use, and more OpenOffice than web 
stuff, you certainly can go higher on the server load. I could see our 
servers handling 20-40 classroom desktops fine, if for no other reason, 
most will be sitting idle at any one time.

I second the suggestion to put gigabit between the server and client 
switch. That made all the difference for us. 10/100 would absolutely 
choke beyond 5-7 clients on heavy internet activity. The other 
suggestions are wise, too. We opted for SATA (10k rpm) which seem 
generally fine and someday, I'll get around putting them on RAID 1- we 
have a scsi RAID in our file server which will take off some of the 
load from the K12LTSP server, disk performance doesn't seem to be much 
of an issue. If you can afford fast scsi disks, then, by all means, do 
it, of course.

Regards,
William Fragakis
Morris Brandon Elementary