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Re: Linux Server





Eli Marmor wrote:

> > Hi, Well we have been thinking along the following lines:
> >
> > a dual PII 350Mhz with 0.5GB RAM, 9GB diska.
>
> You mentioned 20 simultaneous users, each of them runs Netscape,
> XEmacs, TeX, etc. With 0.5GB, each will have only 20MB (assuming the
> system also eats something). I think you need more.

What can I say, If Linux can't handle 20 such users using 512M, you can
trash it now. But, you know what? It easily can. Don't waste your money on more
than .5 Gig.
which is too much anyhow.

That kind of simplistic calculations is completly wrong.



> At least 0.75.
> I also would prefer at least dual Xeon, or even a 4-way.
> (I know that in the past, people could live with less, but these
> specifications are the minimal for today's demands).
>
> > a) does the Linux or programs like the window manager, can run "multiple
> > copies" economically, i.e. if one users needs sau 20MB for the core of the
> > WM, the second user needs much less?, well i am sure that computer
> > system experts know what i mean!!!! i cant remember the currect term to
> > use for this.
>
> Of course things are shared, but only the instruction segments of the
> executables and of the shared libraries.
> But the critical amount of memory, at least in the examples you gave,
> is in the data/bss. For example, a Netscape process may eat dozens of
> megabytes after a few hours. On the other hand, you may wait a few
> years till Netscape 5 will be ready; It is going to be very optimal
> and will not spend resources.
>
> > b) How important is the internal cache of the CPU? is a PII enough.
>
> While the performance of the processors almost doubles itself
> annually, it takes many years for the memory. So the cache is VERY
> critical. The only reason why small caches are enough for most of us,
> is because we are not 20 people on the same machine. Think how much
> cache you would want for yourself (for single user). Now multiply it
> by 20, and divide by the number of processors. Since we are misers,
> divide it again by 2. This is what you need.
>
> Now a small tip: It is very hard to set up a so heavy machine. Offers
> from VA Research and/or Penguin Computing may interest you, although
> they may look expensive. Alternatively, if you find somebody else (in
> this list?) who already has experience with these powers, order him
> to consult you in this project. It's not a play.
> --
> Eli Marmor