systems.
Some common places you are likely to find thin clients in use are libraries for
catalog access and searches, school classrooms and computer labs, and some
airports that make available courtesy terminals for travelers to check email.
Computers that often make excellent thin clients are not advertised as such.
You can look for compact format systems that use an ARM, VIA, or maybe
an Intel Atom processor, for example, and you are likely to find they make
wonderful thin clients. You can even recycle older hardware that would
otherwise be bound for the trashcan and make it useful again as a thin client.
Now that you have a sense of why you might use LTSP and how the network
is created, it is a good time to fill you in on some of the details of what LTSP
is, what it is not, and how it is designed to work. Armed with this knowledge,
you will be able to find documentation to help you decide what you can
afford to buy, how you want to configure it, and whether this configuration is
applicable and useful to your situation.
LTSP is add-on software for Linux that creates a server that can be used to
boot client computers over a network. It allows client computers to access and
run applications on the server while the client remains responsible for input
and display and the server handles data processing and storage. This allows
many inexpensive hardware clients to be used to do things that would
normally be beyond the capability of the hardware, and it streamlines
administration by placing all the configuration and software on one server.
The biggest limitations result from server and networking hardware (for
example, switch or hub, 1GB versus 100MB ports, high-end server and
storage or less-expensive just-adequate equipment).
LTSP Requirements
The minimum recommended specifications for thin clients are a processor
running at 533MHz with 128MB RAM and the ability to boot via PXE (a
common network boot protocol). Nearly any system sold today and advertised
as a thin client exceeds these requirements by a wide margin. We list them
here in case you want to try to reuse old hardware that is otherwise obsolete.
Server and other hardware recommendations are listed in the “LTSP
Installation” section, later in this chapter.
Let’s start by looking at several wiring schemes to show appropriate methods
of using LTSP. The first one, shown in Figure 38.1, is the default install
without an Internet connection and is the simplest way to use LTSP.
From the diagram alone, you can see the main pieces of hardware needed: a