[K12OSN] networking question

Wed Feb 19 15:31:15 UTC 2014

I heard that story too and thought of Cobb county schools' aborted "Give
'em all a MAC" debacle.

Given the poor fiscal support of schools in general, LTSP (and a next gen
thing I'm still poking at) are the most cost effective ways to put students
in front of computers for any reason.

Next Gen Thing: server(s) runs Ovirt and many generic VMs. Student uses
wireless android pad/laptop and connects using spice to get full desktop
with sound and video.

Memory usage is similar using memory ballooning (shared, read-only memory)
as all VMs are identical. Drive space is similar (only /home is different
for each) and it works over wireless and from home. Big advantage is 3-fold
A) GUI for admin of VM environment (and user authentication using freeIPA
has gui as well) B) better stability and security - student can only crash
their VM, not the classroom or half the school. C) can use BYOD (mostly) as
there is a spice client for windows, Linux, Mac and Android.

I've found cheap android laptops for $100. tiny screen and keyboard but
good size for little hands. Can still use this stuff for stand-alone
machine lab setup by mounting /home from nfsv4 server. Good for video work.
Most stuff needs minimal horsepower. Bigger kids can get bigger android
laptops for $170. If schools could figure out how to use freetextbooks, the
backpack load for the kids drops to 3-5 lbs. down from 20-40 lbs.

Flash is still a hog. Wish it would go the way of the dodo bird.

Wouldn't is be cool for kids to be able to say they use a supercomputer
every day at school? !!!

On Wed, Feb 19, 2014 at 10:03 AM, William Fragakis <william at fragakis.com>wrote:

> Jim,
> (btw, hope all is well) big thanks to both you and Scott for your
> exhaustive answers.
>
> We seem to be doing okay on the bandwidth internally, nothing is hanging
> or lagging even with a few clients playing Pandora and a bunch of
> internal rdesktop sessions. I think I'll downstream lower bandwidth
> devices like printers, secondary vms, etc to a second inexpensive
> switch.
>
> Off topic  - heard on NPR how Los Angeles schools thought it would be a
> good idea to get each student an iPad at about $700/device so they could
> "all have computers". That was about the price of my latest kvm server
> with an AMD 8 core CPU, 24GB RAM and 240GB  SSDs in a RAID 1. Not to
> mention the iPads are getting broken/stolen which makes the whole
> process even more expensive. Not that we don't have iPads in our own
> househould. Just that LTSP continues to make a ton of sense.
>
> again, my thanks and best regards to all,
> William Fragakis
>
> > Message: 2
> > Date: Mon, 17 Feb 2014 13:04:01 -0500
> > From: Jim Kinney <jim.kinney at gmail.com>
> > To: "Support list for open source software in schools."
> >       <k12osn at redhat.com>
> > Subject: Re: [K12OSN] networking question
> > Message-ID:
> >       <CAEo=
> 5PzBCO90EcRGrc-w7fwWgknLaYA5NnAyH7YPvvJskKmMFQ at mail.gmail.com>
> > Content-Type: text/plain; charset="utf-8"
> >
> > my ordering for solution:
> >
> > 1) bigger switch (big assumption is existing network is not overloaded
> now)
> > 2) add a secondary "smart" switch above the existing switch if the
> existing
> > switch supports "upstream" port
> > 3) add a second switch downstream with a bonded or aggregate connection
> for
> > more bandwidth (if "smart" primary switch)
> > 4) add a secondary switch with Gbit upstream and 100M ports and set
> primary
> > switch to 100M except for new switch port
> > 5) add a secondary switch upstream with bonded/aggregate connections to
> > multiple nics on server
> > 6) add a second switch off second nic on separate subnet and split the
> > load. This requires a split subnet with dual gateways (each nic) (no
> smart
> > switch required)
> >
> >
> > On Mon, Feb 17, 2014 at 10:30 AM, William Fragakis <william at fragakis.com
> >wrote:
> >
> > > Our k12linux installation is out-growing our present, very primitive,
> > > networking structure.
> > >
> > > Currently, our ltsp server - which also behaves as the firewall for a
> > > number of kvm servers and their vms - connects to 16 or so thin
> clients.
> > > Between the clients, internal servers and printers, the switch to which
> > > the ltsp server is connected to is at capacity (It's a basic 24 port
> > > gigabit).
> > >
> > > We now need to add the n+1 client that exceeds switch capacity. Do we
> > > buy
> > > a) a larger switch to replace the current one
> > > b) a second switch daisy chained to the current one
> > > c) a second switch connected to a second NIC using the same internal
> > > ip/dhcp range (and if so, the recommended manner)
> > > d) a more obvious, elegant, simple, cheaper method that I haven't
> > > considered because I don't know squat (American slang for "not much")
> > > about this stuff.
> > >
> > > thanks to all,
> > > William Fragakis
> > >
> > > _______________________________________________
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> > > K12OSN at redhat.com
> > > https://www.redhat.com/mailman/listinfo/k12osn
> > > For more info see <http://www.k12os.org>
> > >
> >
> >
> >
> > --
>
>
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>

-- 
-- 
James P. Kinney III

Every time you stop a school, you will have to build a jail. What you gain
at one end you lose at the other. It's like feeding a dog on his own tail.
It won't fatten the dog.
- Speech 11/23/1900 Mark Twain

*http://heretothereideas.blogspot.com/
<http://heretothereideas.blogspot.com/>*
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