[K12OSN] rolling your own

[Eric Brown]

My existing k12ltsp server isn't quite doing the job it used to.  It's
a quad P3 550 MHz, with 3gb ram purchased off ebay 2 years ago.  When
20 kids open firefox and OO, things slow down quite a bit, and firefox
may hang on several kids.  I started searching for a new server on
E-Bay, where I found a quad 2ghz machine with 8gb ram for $5k.  My
principal was reluctant to spend that much money on something used
with no warranty.  He said he'd prefer to have me purchase parts and
use the assembly of the server as a teaching opportunity (something
I've done with workstations in the past).

My question for the group is, has anyone done this and encountered
problems with some aspect of the machine in an LTSP environment?

I'm looking at a Tyan board that will take 4 Opteron dual-core
processors, probably 8 gb RAM, 2 gb nics onboard.  I'm not too worried
about disk space.  I've only got 4 9gb drives in a raid5 right now,
and only 44% is in use for about 60 students.  I'm planning on
something like 4 74gb 10,000 rpm drives with 8mb cache.  Since the
board is an extended atx, nearly any case that will take it is usually
a server case with room for all the drives.

Preliminary costs look to be $5k-$6k, which is the ball park I've been given.

Anything I'm missing?  Is this a bad thing to do?  Shouldn't this run
20-25 clients very well for some time?  Is it too much (I'm often
accused of over-engineering anything I build)?  Any comments welcome.

Thanks,
Eric Brown