Which hardware?

[Dan Young]

Knut Yrvin wrote:
> Torsdag 15 juni 2006 18:07, skrev simon.balderson at btinternet.com:
>> Essentially, my question is - does anyone have experience with
>> Edubuntu/LTSP for around 32 clients? Most of the examples I've seen
>> online are for 10 to 15 machines. Will 4GB of RAM on the server do
>> it, or will that slow things down? 
> 
> Probably 2 GB is enough. Every client in a thin client network uses 
> around 64 MB of memory. The server software itself uses around 256 MB 
> of memory with no clients. Because of an error in FireFox 1.5 with 
> caching pictures 3 times when using tabbed browsing, you should 
> probably beef up the memory pr. client to 128 MB on the server side. 
> 
> 15 * 128 MB = 1920 MB 
> 1 * 256 MB = 256 MB 
> Sum = 2,1 GB RAM ~ 2 GB RAM (on a server with 15 thin clients)

Uh, so 4GB for the 30+ Simon asked about? 4GB is the minimum for this, IMHO.

> That said. We know a lot of schools that runs 60-70 thin client on one 4 
> GB RAM Skolelinux/Debian-Edu server with on  a 100 Mbit/s switched 
> network. The One Laptop per Child project has advised the Mozilla 
> Firefox guys to clean up the memory eating bug in that browser, so it 
> will probably be fixed in next main version of Firefox. 

Could be a while, and FF is a pig right now. You might look at setting:
pref("browser.sessionhistory.max_total_viewers", 0);
in the default Firefox prefs to cut back on the gratuitous caching in a
large memory environment:
http://kb.mozillazine.org/Browser.sessionhistory.max_total_viewers

> The thin client needs at least 128 KB RAM if you run Edubuntu or 
> Skolelinux 2.0 because of the "memory hungry" Muekow implementation of 
> the login manager, and the lack of swap over network: 
> 
> http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=367606

s/KB/MB/

One more recommendation; think about installing and using prelink to
speed up application launching. It's supposedly most effective on large
C++ applications (read: KDE, OpenOffice, Firefox). 30+ clients all
launching OO Writer at the same time can be interesting. ;-)

Don't know how Ubunteros feel about prelink (it's in universe); it's
installed by default on Fedora.

-- 
Dan Young <dyoung at mesd.k12.or.us>
Multnomah ESD - Technology Services
503-257-1562