[K12OSN] Scalability (long email)

Julius Szelagiewicz julius at turtle.com
Wed Apr 7 01:46:45 UTC 2004

> My fellow geeks,
> I need some help.  Possibly some of this can go offlist, as we've grown in
> size significantly recently -- but this is really the only place I know to
> get the answers I need.  WARNING: This email will probably be long.
> I just left a meeting with the other school supervisors in our district,
> and
> after the monetary projections -- our district is more interested in my
> fanatical ravings about OpenSource than ever before.  I never thought I'd
> get
> to say, "I'll have to hear a darn good reason that we need to purchase
> licenses from Microsoft rather than keeping Suzy Mathteacher on staff..."
> anyway, on to my questions:
> I have 3 schools, all connected via fiber.  There are approx 30 classrooms
> per
> building, with a variation of 10 & 100mbit connections internally.  The 2
> big
> directions I'm looking at would be to have 90 "mini-labs", where a teacher
> gets a new white-box Pentium 4 computer, and have it serve as a classroom
> LTSP server to 5 or 6 "junker" thin clients for the students (much like
> the
> original case study Paul Nelson put up several years back).  If the
> student
> management system won't work under Wine -- that teacher computer would
> have
> to run win4lin or some such solution.
> The other option, is to go completely with thin clients in the classrooms
> --
> but then I worry a GREAT deal about scalability and network bandwidth.
> Management-wise, the thin client solution makes a lot of sense (of course)
> --
> especially since I doubt I'll be having any help from outside hires or
> teachers with release time.  I really worry about the scalability of the
> servers and network though... any real world examples I could pull from?
> I considered that if we go with the Pentium 4 computers on a teacher's
> desk as
> a mini-LTSP server, that they could all be kept "pure" by a nightly rsync.
>  I
> realize there would be a few individual settings that would need to be
> there,
> but many of the config files could be similar.  Sadly, I'm concerned about
> the life of the Pentium 4's though, as technology is so quickly outdated.
> What might be a server today could be worth little more than a thin client
> in
> 5 years, while if I go with thin clients everywhere, they will
> theoretically
> be good for much longer.
> Some final actual questions:
> Does anyone rsync servers in the fashion I suggested?
> Does anyone have any good "devil's advocate" type anti-linux slams they've
> gotten, so I can prepare to defend myself?  I am confident, but like to be
> prepared.
> Is there a listserv dedicated to open-source curriculum (by that I mean
> using
> open-source software as a part of daily curriculum)?  If not, why don't we
> start one?  Sharing lesson plans, hand-outs, daily integration issues, etc
> --
> many of my teachers would join, where as they WOULD NOT join this list.
> (and
> I wouldn't want them to...)
> Are there any cases of "great press" that you folks have gotten because of
> the
> savings OSS has provided?  I pictures us being a shining example of using
> tax
> dollars wisely in tough times, and I plan to market the snot out of that.
> You Oregon folks that have been doing this for a while -- have you gotten
> a
> lot of "atta-boys" from the communities?  How has the adoption of OSS as
> an
> alternative been taken as a whole?  Have you had any organized opposition?
> Sorry to take so many bytes in your mailbox -- but this is a crucial time
> for
> us, and I need some advice/guidance/brainstorming from, well, from you. :)
 borne by experience, some caveats: 1. dump the 10TX, it just is not
adequate for ltsp style solution when you have the mongrels nipping at
your heels. 2. p4 is ok, provided you go with multithreaded processors -
most 3+GHz are multithreaded, but not all - the real difference is that
they make the server behave as if it was a 2 processor system. this is
very, very important, since no single process will lock the server. 3.
don't count on Wine to run all the M$ apps, it just won't happen. Scream
bloody murder and remind everybody incessantly that evry buck spend on
software goes to billg and he doesn't teach at your schools. destroyed
budget is a great enabler of open source software. good luck, julius

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