specs for running 35 machines

[Jim Kronebusch]

On Wed, 15 Aug 2007 00:34:17 -0700, Sameer Verma wrote
> Hi all,
> 
> Does anyone on the list have specs for a server that can run 35 clients 
> simultaneously? Apps are Firefox, OOo, Inkscape, GIMP, etc. We have P4 
> desktops with 100BaseT and switches at 1000BaseT.
> 
> Sameer

I have copied this to the users list as that is probably the most appropriate list to
ask this question.

I assume you are intending to run a default Edubuntu configuration with the P4's as thin
clients.  It is hard and a little scary to give an exact configuration as to what will
run your workstations as every setup is a little different and has a little different
use.  Also concurrent users are more of a concern than total clients.

I would say for 35 clients simultaneously running any two of these apps you probably
want a minimum of a Dual processor machine (recommend AMD Opteron or Intel Xeon
processors running 2Ghz or above).  As far as RAM I would recommend a minimum of 4GB and
that you run a 32-bit OS with the linux-image-server kernel to take the most advantage
of it.  Be sure the machine will handle up to 8GB in the future just in case performance
isn't what you desire, then you have the option to increase the RAM.  As far as hard
drives go I would use SCSI.  RAID 5 is your most fault tolerant solution, but lacks a
little in speed.  If you can afford it go with a RAID 1+0 (mirror of stripes) which will
give you excellent speed and reliability.  If neither of these is an option at least run
SATA with a mirror.  I personally would team two GB NICs together in the server using
this tutorial:

http://www.howtoforge.com/network_bonding_ubuntu_6.10

I go with mode=6 and change the aliases to "alias eth0 e1000" to handle the GB nics. 
Also there are two typos in the tutorial, the references to "/etc/modeprob.d" are
missing an "e" and should point to "/etc/modprobe.d".

I like to keep a maximum of 15 machines per GB NIC to avoid a bottleneck, the teaming in
mode=6 will give you failover in the case of a NIC going bad, and will also give you
enough bandwidth to handle the traffic.

I would recommend dual power supplies if possible for failover, but that isn't a must if
cost is an issue.

If this is your only server and you will not have a spare, I would recommend purchasing
from a supplier that can offer quick response times on parts (such as Dell's 4hr same
day parts and labor).  It might cost you a little extra up front but keeps you from
being down for a week while waiting for a new motherboard if you have a major failure.

I hope that helps, 
Jim

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