[ILUG] Re: headless X server

[Niall O Broin]

On Thu, Apr 19, 2001 at 09:23:37PM +0000, Petra wrote:

> I want to build a headless Xserver for a school and I was wondering
> what guidelines there are for physical Memory per concurrent user.
> 
> I hope to get 30 or so pentuim 200MMX machines acting as Xterminals
> only, connecting to the server to run Star Office.
> 
> I'm hoping that memory page sharing will be used to cut down on the
> amount of physical memory required.
> 
> Any pointers on such information?

Hopefully Caolan will be able to provide some good information from the
source, so to speak, but the question intrigued me, so I sucked it and saw.
As I write, I have four instances of Star Office 5.2 running on my notebook
which has 192M RAM and a 700MHz P-III. Each fresh instance of SO dropped the
amount of free memory by between 13M & 16M. I currently have 50 soffice.bin
processes running and that leads me to a couple of questions of my own. I do

for x in niall phil eleanor james
do echo $x;ps aux|grep soffice.bin|grep $x|wc -l
done

and I get 

niall
     13
phil
     14
eleanor
     15
james
      7   

Why the differing numbers of soffice.bin processes ? All sessions are
totally quiescent. james was originally running on the notebook's console,
also with 7 processes, and I decided to make him a remote session too to
eliminate any difference, but still the big difference in numbers of
processes. Looking at top, I see that RSS for a soffice.bin process for
niall & phil is 48M, for eleanor it's 56M but for james it's only 43M.
Curiouser and curiouser, no ? Another interesting point is that each fresh
instance of SO took about 5 seconds pressing Enter to having the desktop on
my box - not too sloppy, although the box I'm displaying on is probably a
somewhat faster X terminal than a P-200 (I can do you a good deal on a bunch
of Matrox Mystiques to upgrade those P-200s - the Mystique is a very snappy
card for X)

Anyway, to get back to the point, none of these users were doing anything
and Star Office's memory usage shoots up when you do certain things -
presentations are one example. I'd suggest that you think of budgeting for
32M per user. This means that 1G of RAM in a box should suffice. 

However, you'd want to consider processor usage too & I've no idea where
that's leading - the more processors, the merrier.

You'd buy Dell's lowest end server (Poweredge 300) with 1G RAM, 2 x 800MHz
P-III and 2 x 40G IDE drives for about IR£2500 but you should be able to put
something together yourself for much less, if you're that way inclined (or
buy the Dell with minimum memory and upgrade it yourself from Crucial or
somesuch. Dell charge £1363 to upgrade a PowerEdge 300 from 64M memory to
1GB - 1GB of RAM from Crucial INCL. delivery and VAT is < IR£450). If the
budget's a bit healthier, consider something like Dell's PowerEdge 1400
which you can bump to 2G RAM and which comes with SCSI disks.

Those numbers make interesting reading - a Linux server to provide each box
with Star Office for about IR£60 - less than the cost of the memory upgrades
you'd probably need in the Pentia to run 'doze effectively, not to mention
the savings on MS Office and 'doze upgrade license fees, and the immunity
from Outlook borne virii.


Do let the list know how the project goes.




Regards,


Niall  O Broin