User story: Edubuntu lab running 43 clients --- needs some tuning

Wed Jan 18 09:35:25 UTC 2006

Hi Hendrik,

Thanks for the mail, and sorry for the very delayed response...
I think many ppl are just returning from leave and are catching up with
mail, as I was/am... I am sure you will get more responses soon.

On Wed, 2006-01-11 at 17:41 +0200, Hendrik Boshoff wrote:
> To the Edubuntu-Devel mailing list:
> 
> Today was the first day of our new school year, and we had a server and
> 43 client machines running standard Edubuntu at the Laerskool Unika
> (http://www.unika.virafrikaans.com/) in Johannesburg .

Awesome! I am thrilled to hear this. I live in Cape Town, but I grew up
and went to school in Johannesburg, so I am very happy to hear that you
are pioneering with Edubuntu up there.

>  The server is
> brand new and fairly high end, and the clients quite old, mostly PII 266
> MHz and Celeron 333 MHz with 64 MB of RAM. There was no instruction to
> speak of, but the 7th grade children enjoyed the games and the novelty
> immensely.

Good to hear. :)

I'd love some more feedback about what works and what doesn't from a
children's and educational point of view. i.e usability and applications
rather than h/w and technical specs etc...

We rely on feedback from educators and people on the coal face to know
what is needed, and what people like and don't like.

> I am very excited about the possibilities of Edubuntu, and I want to
> thank everyone involved in creating this environment. 

Thanks for the positive feedback. :)

> Unika's lab does
> not have Internet connectivity yet (apart from a makeshift dial-up) but
> the number of applications available in the Universe is mind boggling.

Indeed Universe and multiverse have a huge array of stuff to chose from.
As applications are refined and secured and fully tested and certified
we will be able to add more to the main install (disk space permitting),
we may also introduce an additional application disk (or DVD) over time.

> Our server has a dual Xeon 64 motherboard with CPUs running at 2800 MHz,
> and 4GB ECC RAM. Hard disks are 3x 73 GB SCSI 10 000 rpm in a RAID5
> configuration. The Gigabit network card connects to a 3Com switch with
> 24+2 ports (100 & 1000 Mbps). The other wideband port connects to a
> second switch, and the 43 client machines all have 100 Mbps NICs.

That sounds pretty good to me, but I will leave our technical guru
Oliver to answer...

> I have been working *many* hours (with help from my children aged ten
> and thirteen) during the last six weeks' holiday mainly to get the
> hardware reconditioned, the various NICs to boot, and testing which
> video cards would run X.

Gosh I am impressed, and well done to your kids for getting involved
too. Maybe they can become Edubuntu Ambassadors in SA.

>  It was nothing like the Edubuntu blurb claiming
> an educator could get a lab up and running in an hour with donated
> machines (http://wiki.edubuntu.org/EdubuntuWiki).

Oh dear, that is not good news. I hope we can establish what and why you
had problems. We need to try to make and keep it simple and easy.

>  I am proud to have
> kept 75 machines out of the landfill however, having passed 35 working
> P1 166 & 200 boxes on to another school.

Commendable indeed!

>  One current minimum for an
> Edubuntu client seems to be 64 or 48 MB of RAM, although this may depend
> on the video card. Has anyone managed to boot a client with only 32 MB?

There is an easy formula for an Edubuntu lab, which I got from Oliver,
This may assist you.:
 - LTSP server:
 - CPU: as fast as you can get, the more the better, don't take
something
below 1 Ghz if at all possible.
 - MEMORY: 256MB for the server itself and at least 100-128MB for each
client you want to attach.

 - Workstation: the same requirements Ubuntu has apply to Edubuntu plus
we need ~500MB more disk space for the edubuntu apps. (This is for stand
alone workstation installs not thin clients - in case that's not clear.)

> Of course I want to get the maximum out of this setup, and it seems to
> need some tuning. Can anyone suggest tools for finding the bottlenecks?

Sorry I can't help here, I hope someone else can...

As well for the questions below...

> The lab has not really been given a stress test, but it easily supports
> a class full of learners playing games. When OpenOffice Writer is
> activated on only a single client, it takes about 10 seconds to load. If
> ten clients try at the same time, it gets so slow that it seems to hang.
> 
> Looking at the system resources, the network seems far from saturation
> at about 200-300 Mbps, and the memory far from used up at about 1.5 GB
> out of the 3.5 GB available. However, the CPU bar often goes to 100%,
> and stays there for long stretches.
> 
> So it would seem that the server CPU is the limiting factor. Firstly, we
> are running the 32 bit version of Edubuntu software on a 64 bit CPU,
> because of the mixed environment problem in Breezy. I am a bit wary of
> running Flight 2 of the next release in a production environment. That
> should improve after April. Secondly, I need to know whether the second
> CPU is used at all. How can I find out?
> 
> What else can you suggest to speed things up? Lowering the colour depth
> from 24 bit? Who has run an Edubuntu lab of roughly this size, and how
> is it configured?
> 
> I still have use for some Edubuntu posters and other promotional
> material. I am currently the only evangelist around here :-). At some
> point I want to invite teachers from other schools to come and see what
> can be done with old hardware.

Excellent thanks. Unfortunately since we are still a community project
we have no promotional material at all.

You can apply for an Ubuntu Promotional Pack though.
See:https://wiki.ubuntu.com/UbuntuAtConferences for details.

> I look forward to the live CD of Edubuntu, which I want to give to every
> pupil in the school for home testing, and I would like to see a DVD
> distribution with many more packages.

Yes agreed.

We are hoping to be able to do a limited CD print run with the next
release...

regards
JaneW

> Thanks for any input.
> 
> Hendrik Boshoff
> Associate Professor
> Department of E&E Engineering
> University of Johannesburg

p.s. I studied Electronic Engineering at Pretoria University :)

-- 
JaneW
_____________
Jane Weideman
mobile: +27 83 779 7800
Canonical Ltd.