Re: [seul-edu] How big a server?

[Les Richardson <richl@mail.tfsd.sk.ca>]

A friend of mine is running a _very_ large Sunray appliances (X Terminal
Wannabees). Using large Sun 450's for application service bogged down
since the Sunray software (which implements the rest of the X Terminal
emulation) also runs on the Sun server. The solution is to move
application service and login/homefolders onto separate boxes. 

If considering application services for X display servers running on NT
boxes (although Dual Boot would be nice and entire drive could be
ghosted...(this is the setup we run)) you will have to consider the memory
requirements for a running app per user. If we assume 100Mb per user for
example, then 50 users will need about 5GB of Ram. Typically one can stuff
about 3-4 GB per server (even a Sun...4GB per processor). So perhaps build
a couple of server to start.

I would suggest, for starters, build a nice Dual Processor System with 4GB
of Ram using either a Systemworks board (about 10 of these running
locally) or one of the Asus CUV4 thingy's (Dual Processor also).

Both have onboard scsi with LVD support. I would put 4+ 9GB drives into
those things (more spindles = better so don't buy big drives). Intel
NIC's. Good case, IDE CD, etc. 

These things should cost about $3000-$3500CDN to build (a lot less in
USD...<sigh>).

The local division is also implementing "slim" application servers which
are somewhat cheaper boxes (ie. just really workstations with LOTS of
ram..single processor, ide drives). Let users "see" all the app servers
when they log in...They can see how many users are logged into each
machine, and choose which one to log into....voila, intelligent load
sharing.

These app servers are all clones and use rsync to mirror off a master.
(i.e. easy to maintain and add apps, etc.)


 I wouldn't be that keen to build a "mother of all servers". Single point
of failure, although simpler management of course.

My $0.02CDN.

Les Richardson
H. Hardcastle School
Edam, Sk. Canada



On Mon, 12 Nov 2001, Jan Hlavacek wrote:

> Hi everybody,
> 
> I am sure there must be somebody out there who has done something
> similar and can give me some advice: 
> 
> our college has several student labs running NTs. Our department (math)
> is currently the only department that uses Linux, and our usage has been
> so far restricted to a web server running WIMS. We always wanted to make
> some of the excellent unix math software available to our students on
> the desktop. We have a budget proposal for a linux lab, but that will
> take a while to get through (if it ever goes through). 
> 
> Lately, our chemistry department contacted us asking for help setting up
> some sort of unix solution for their students.  One possible solution I
> found is using an x-server on the NT machines in the labs to login to
> one linux server. I managed to get cygwin with xfre86 running over the
> network from a SMB share, and it works beautifully with my desktop linux
> machine. However, to actually be able to use this we will need powerful
> enough server to support many simultaneous connections. And this is wnat
> my question is:
> 
> We may have several hundreds items in passwd file, and as much as 50
> (usually not more than 25, but let's assume two classes working at the
> same time) users logged in at once.  The applications used would be some
> mathematical software (CAS of a sort, octave, maybe kseg or drgenius),
> molecular modelling software and some other computational chemistry
> stuff, so it may be kind of computationally intensive, but i wouldn't
> expect anything outrageus, these are undergraduate students.  Does
> somebody have any estimate about how big machine (memory, CPU) am I
> looking for?  
> 
> Thank a lot for any suggestions or pointers to information.
> 
> -- 
> Jan Hlavacek                                            (219) 434-7566
> Department of Mathematics                             Jhlavacek@sf.edu
> University of Saint Francis               http://www.sf.edu/jhlavacek/
>