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Re: [LUG] Remote Access to a Central Box (LTSP et al)

 

Dave wrote:
> I would like to have a central box with terminals hanging off it around the
> house so I can play music, surf the web and (if I ever get that clever)
> control X10 devices all via very minimal terminal type machines (i.e. no
> major hardware that will all be in the central box) connected via Ethernet
> not wireless (my walls are too thick, like me!).

You appear to only want text terminals or is each terminal actually
running Gnome/KDE/Enlightenment etc? Note that running any kind of GUI
across a network connection is slow and consumes vast amounts of network
bandwidth for tiny operations, increasing the load on the server.

Dumb text terminals need almost no hardware on the machines themselves.
Lack of a hard drive means no moving parts, less need for fans and a
much quieter environment. To run a GUI, you're going to need a full
desktop PC for each terminal machine; maybe old and underpowered for use
as a dedicated workstation but with hard drive, graphics card, fans,
etc. In a word, noise.

Alternatively, separate machines operating as peers is even easier. You
can choose to share data between boxes when appropriate and you can
choose not to when it would just consume network bandwidth for no
purpose. You can use sophisticated tools to share data - maybe share
your /home/ directory using subversion, share your images using a simple
gallery package and Apache, share your music via NFS and share your
email via IMAP. Instead of lumping all that on one server, you could
have one machine that does subversion and email, one that serves music
and one that serves images.

None of those machines need to be the latest and greatest. I'm using
this setup and my email/CVS/IMAP machine was built in 1992. It's had a
new power supply since then (thanks to Neil S.) but otherwise, it is an
unchanged Pentium1 90MHz machine, 4Gb hard drive (yes 4, not 40 or 400)
with (IIRC) 128Mb RAM. I couldn't install XP on it even if I wanted to,
yet it runs Debian stable perfectly and has done for years. (Since about
July 2000.) It's been rebooted twice in 3 years and not had any
unscheduled downtime in 6 years. It just sits on the end of a network
cable, doesn't care about a GUI or anything else, it just serves data
across the network.

Even if I do need to do some work on that box in the future, the rest of
the network continues operating - try that with a central server....

> I can't though discern the difference between something like the Linux
> Terminal Server Project and Remote X as to which would be better for my
> needs; I know LTSP allows local USB devices etc to be treated as if they are
> on the main system but if that is the only difference between the two
> systems then I would rather not use it.

Why? LTSP is probably the way to do this - as originally described.

> As I see it LTSP is really a Distro on a distro so why not stick Dsl,
> Xandros or whatever on a USB Key or something and use that to Remote X to
> the central box? Is there limits to how many X systems can run off the same
> box at the same time?

Network capacity, server load, time it takes you to not fall asleep
waiting for a keypress to show up in a text box . . .

LTSP is about optimisation, Xandros needs to be tweaked to run this way.
USB keys aren't the complete answer either - remember that flash storage
has a limited read/write lifetime.

> I would really appreciate some help here becuase the connection betweeen
> 'Terminal' and 'Server' is a big stumbling block for me which I can't seem
> to get over.

The less data needs to be transmitted between the two, the more useful
the setup becomes. Keep the amount of data low and you can use simple,
cheap machines that are quiet and don't get in the way of your work. Put
too much data through that ethernet cable and you'll need a really
powerful server machine (really noisy) and also
more-powerful-than-otherwise-needed terminal machines too. Too much
network data and you'll have trouble squeezing your own data through the
same cables. If the terminal machines need to run "apt-get upgrade" then
you'd better make sure you don't want to use the GUI at the same time.

Sit down and think this out. You may find it much more useful to simply
have one or more machines in a converted bedroom upstairs, run an
ethernet cable to the downstairs and use a quiet machine downstairs,
e.g. a laptop, especially a Mac laptop as they are often a lot quieter
than PC versions and run GNU/Linux just as well.
(i.e. that's what I do.)

Consider the benefits of having a "terminal" that you can take with you
- complete with rsync'd copies of network data.

Also consider that having separate machines is a benefit in and of
itself - backing up the data on that central box could be a problem.
With separate machines working in a peer environment rather than
client/server, you can back up each one onto the others using rsync. A
backups to B, B to C and C to A. Reduces the risk of a single hard drive
failure removing all your data.

> Thanks in advance for any help and apologies if I've made any faux pas with
> mail etiquete as this is my first mailing.

No problem. You got everything right - despite using OE, you didn't send
HTML, your text is clear (mostly) and your questions are understandable.

-- 

Neil Williams
=============
http://www.data-freedom.org/
http://www.nosoftwarepatents.com/
http://www.linux.codehelp.co.uk/


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