Maximum Addressable RAM

[Gavin McCullagh]

Hi,

On Sat, 17 May 2008, Butch Arias wrote:

>   (1) Will the 64-bit version work with Intel Core-2 Duo?

It should do, yes.  Though certain (usually proprietary) software won't
work on 64-bit.  The most obvious example is there is no 64-bit Adobe Flash
plugin so if you want eg. youtube, 32-bit might be a better choice.  As
Oliver said, the -server kernel will let you use > 4GB ram on 32-bit.

>   (2) If it will work (or I will use an AMD 64) would there be NO problem if
> the thin clients are 32-bit?

That should be fine.  The clients can run a 32-bit environment with the
server on 64-bit -- some setup is required, but it's pretty doable.

>   (3) I tested a unit (32 MB RAM) and it worked with Edubuntu 7.10. Is 32 MB
> enough or I need  64 MB for 8.04?

A thin client with 32MB RAM?  That seems a bit short of RAM, but if it
worked on 7.10 I guess it probably should on 8.04.

>   (3) In case the setup for 64bit Server and 32-bit client will NOT work:
>       (3a)   Will it be possible to divide the thin clients (to divide the
> CPU load) across two servers (4 GB RAM each) but still share a common disk
> system?

Yes.  You can put all home directories on a single server and have one or
all of your thin client servers mount them over NFS.  You would then need
to setup a central user system (eg LDAP, NIS) so that the usernames,
userids and passwords were common to all systems.  This is a bit of a
hurdle.

Some people have divided clients up simply by running a DHCP server on each
server and letting the thin clients boot whichever responds first (the
theory is that a busy server responds slower, so this load balances to some
degree). 

>       (3b)   Will it be better to have two separate network servers and use
> just enough thin clients until the server runs out of RAM required for the
> clients? How may users access their files in case they logged in the other
> "network?"

I don't really understand this question.  I'm not sure how much RAM the
average edubuntu user takes at the moment, but I would hope you'd get well
above 16.  One big server has advantages in that you don't have to split
the users at all, don't have to manage multiple systems, etc.  Several
smaller servers has the advantage that if one dies or is giving problems,
your system can keep going using the other servers while you go and fix the
problem server (which might involve obtaining parts, etc).

Gavin