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45 Minutes to a Linux Terminal Server - reallylinux.com
45 Minutes to a Linux Terminal Server
By Mark Rais, senior editor for reallylinux.com
For an introduction to Terminal Servers, first read: In Business the Desktop is Dying
With a Linux Terminal Server and
thin-clients, a business can remove many of the costs associated with
maintenance, support, and licensing of countless desktop PCs. Thanks to the exceptional efforts of the Linux Terminal Server Project members, such a switch can be both cost effective and efficient.
This article summarizes how one
small business made the switch quickly using the extensive effort that resulted in the creation of the K-12LTSP prepackaged release. This ready to use
package comes preloaded with every program needed. Most importantly, it can be installed and used within 45 minutes and makes a terrific prototype server. Now any small business can try out the power of a Linux Terminal Server with nominal effort.
If you're ready to begin installing a
prototype Terminal Server, please skip ahead to Step 2. Otherwise, read on.
Step 1: What is a Terminal Server and
Why Should I Care?
A terminal server is a computer running
certain programs that allow other PCs to directly connect and use its
resources and applications.
The server is accessed through a
variety of thin-clients, which are inexpensive PCs that have a
network card connection.
For example, an office may have five
desktop PCs attached to the network. By connecting them to a
Terminal Server, these PCs no longer need to rely on their own hard
disks, memory, CPU power etc. Instead, they connect to the power and
capacity of the single server. This one server offers each of the
thin-clients (terminals) access to necessary applications, the
Internet and Intranet, storage and print devices.
Such a configuration offers the
following overt benefits:
- Greatly reduces desktop PC
support, maintenance, and upgrades
- Places all configuration and
applications in a central server model
- Greatly reduces software licensing
costs
- Simplifies I.T. operations
- Operates on older or outdated PCs,
as the performance is predicated upon the server
- Easily integrates with existing
servers and infrastructure such as Windows NT Servers
- Allows the use of Linux and
OpenSource software with almost no installation burden
The Perceived Barriers
Ironically, most businesses today
already employ a part of this terminal to server model, whether they want to or not.
Most businesses today, especially those
operating Microsoft services and servers, rely heavily on central
servers to perform tasks such as license and desktop PC management,
email and data storage and delivery, and printer sharing. All of
these capabilities come from the central servers.
The PC sitting under the
desk is nothing more than a place to store licensed applications.
Not even individual user data exists on the hard disks. In most
companies the data is stored on a SAN (storage area network) and only
accessed through the desktop PC.
So the Terminal Server offers a major
benefit to existing Microsoft based organizations. It allows you to
run applications and maintain those applications and desktops with a
single server that requires NO LICENSING BURDENS. Moreover, the
constant upgrading cycles no longer apply. You can keep the old PCs around for
a decade. They don't need to receive upgrades. Instead all hardware
level upgrades occur only on the Terminal Server. In most settings a
Linux Terminal Server costing no more than $2,500 can easily support
twenty thin-clients.
If you need more clarity how a Linux
Terminal Server can help your business, please read my article:
Linux in Business. If you desire to use a Terminal Server in an
educational environment then please read my article on Linux in the
Classroom.
Step 2: Setup Terminal Server Hardware
In the numerous Terminal Server
installations I've done, this step usually required less than 45
minutes. In most cases the slowest part of this first step is
waiting for the software to install on the server and reading through
my text!
Step A: Choose a Server
Obviously, if you have a nice fat
budget, getting a more powerful system will all the more dramatically
increase each individual thin-client session.
However, in a number of cases I
installed Linux Terminal Servers for non-profit organizations and
applications where there was no budget. This led me to choose the
following high reliability, low cost setup.
One of my frequently used
configurations is as follows:
Dell PowerEdge SC420
512MB RAM
400MHz BUS
2.2GHz Intel Celeron Processor
2x 80GB 7200 rmp hard disks
2x PCI 10/100 Ethernet cards (Linksys etherfast)
It's obviously not a high end
server configuration. This is a prototype server I've used countless times because
all of the hardware is fully compatible with Fedora Linux and the
total cost of this server is less than $500.
If you are a government or educational leader, Rais has extra server he may choose to gift to your
organization -- if you are serious about using LTSP. This gift offer is provided exclusively
to organizations of Rais' personal choosing, in India, Australia, and New Zealand. You may wish to contact him.
This is not a general offer, and quantities are very limited.
If your budget can handle more, then by
all means you'll see even further performance gains. However, this
particular server can support a handful of thin-clients without any
fuss. Eight simultaneous users doing basic things like writing
documents with OpenOffice.org Writer get reasonable performance through
this setup.
As a rule of thumb, the Linux Terminal Server
(TS) should have:
64MB of RAM for each thin-client
250MB of disk space for each user /home
directory, plus an additional 6GB for Linux
100MB or faster Ethernet connectivity
Once you have your server, what ever
the brand you prefer, you're ready to move on to the next step.
Step B: Install the Network Cards
It's true, most every server on the market comes
with pre-installed network cards. I caution you that the most
important thing is to ensure the network cards are fully supported by
your Linux flavor. It's also a bonus to find cards that are highly
reliable and inexpensive.
In my case it was cheapest, guaranteed
compatibility with Fedora Linux, and easiest for me to use two
Linksys Etherfast 10/100 PCI cards purchased seperately. I like these cards and have
installed many of them. They sell for less than $20 in most stores
and provide excellent network connectivity. You can choose whatever
you want, just make sure the cards are fully supported by Linux and
that they are reliable.
For a proper installation you need two
network cards. The first card is the “external” card that
handles all data being passed to the internet router/gateway. In my
case the first ethernet card (eth0) will support the DSL broadband
connectivity for the TS. The second card (eth1) handles the
“internal” network connectivity to the thin-clients.
Step 3: Install Linux
Terminal Server Software
As with many aspects of Linux, you will find there are a variety of options for installing your terminal server. You may choose and install your favorite Linux flavor and then install the LTSP programs, or you can use a pre-configured LTSP installation.
Ofcourse, no one should simply grab Linux CDs and start installing and integrating within a
business setting. I always recommend integration begin with a
prototype server on a business subnet. You can read more
regarding integrating Linux in any business
in my article: Moving to Linux.
I decided to use the K-12LTSP CD set since it is easily installed and comes with everything I need for a small business setting.
Notice, the K-12 version is actually
the packaged release used for schools. There are a lot of pre-installed software tools and teaching aids you can simply delete later. It uses the Fedora Core 4 base.
For more information about LTSP updates please visit the LTSP.org site.
For a super easy to install
prototype, the K12LTSP package is exemplary. This ready made package comes preloaded and preconfigured with so many software needed in a small business setting including:
OpenOffice.org suite with word
processor, spreadsheet program, and presentation tool all compatible
with Microsoft Office;
rdesktop (ability to connect to
Microsoft Windows terminal servers);
SAMBA (ability to do file-sharing with
Windows servers);
and over 60 other programs such as
Firefox, Evolution email software etc.
For a business prototype there is currently no
easier way to get immediate benefits of a Terminal Server.
Start the Installation
Start the installation process by
choosing the Linux Terminal Server from the K-12LTSP installation menu.
I recommend you do an automatic
installation and partioning rather than use disk druid.
As the installation proceeds, you will
be asked to confirm NETWORK DEVICES.
This is a very vital step. Select the
devices you will be using. In my case the eth0 will be connected to
broadband and needs to be setup to receive it's IP address via DHCP.
The second device needs to be setup to support the TS and should be
given some default IP address. If you want to know, the LSTP usually
sets the server as: 192.168.0.254
You can include this now if you wish,
or do it later in the configuration.
You will be given the opportunity to
select packages. I strongly recommend you make sure that at least
these packages are included:
Linux Terminal Server
Desktop shell (GNOME)
Office suite (OpenOffice)
Web browser (Mozilla)
Email (Evolution)
Instant Messaging (depends on your
business need)
Sound and video (this allows for video
conferencing and voice dictation)
Be sure to check all three boxes under
System to include: Administrative Tools, System Tools, and Printing
Support.
It is useful also to check under
Server: Server Configuration Tools, Web Server, Mail Server (unless
you plan to utilize an existing Exchange server), and Windows File
Server.
As the installation process completes,
you can also choose to Install from the Additional CD. Once done,
you're ready to run your first Linux Terminal Server sessions!
Step 4. Activate Your Network
Connectivity
Once your TS is up and running, you
should ensure that the network cards are properly running.
From the main menu, choose System
Settings, then Network. If you've never setup a network card for Fedora you may benefit by first reading Post Installation Configuration. For now, highlight
the ethernet card that will be used for internal network connectivity
to the thin-clients.
Make sure it has the correct
configuration. Press the Edit button.
You should ensure the proper IP
address (usually 192.168.0.254), and your Subnet mask (often 255.255.255.0 on most networks) and your Gateway (just use a dummy like 123.123.123.1 if you don't know for now) is included. You MUST obviously adjust these depending on your business network. Also note the very important first box
that should be checked: Activate device when computer starts.
Once you press OK, you will return to the
Network Configuration window. From here choose the DNS tab and be
sure to fill in all the necessary data.
Please make sure you assign a hostname. I've assigned this system the hostname:
linuxtsp. You do not have to include any DNS information if it does
not apply to your situation.
Now press the Hosts tab.
Here you will see 256 IP addresses
listed. All you need to understand at this point is that your TS is listed as the
last entry usually ending with .254. The top entry alias "ws001" is the name that will get
assigned to the first terminal thin-client that connects to your
server. The second alias "ws002" will get assigned to the second one, and so on.
Press the Device tab again and
highlight the ethernet card you will use for internal network
connectivity again. Now press the Activate button to ensure it is
activated.
You should see a little window appear
and then disappear.
You're now ready to connect
thin-clients to the server!
If you had any issues or need more
details regarding network card setup in Fedora, please read this.
Step 5. Create User Accounts on the TS
From the main menu, choose System
Settings, then Users and Groups.
Press the Add User button to begin
adding new users for the server. Remember that these are users that
will login to the server from their thin-clients. Access
restrictions and proper user password and security procedures should be
applied for this step.
Once you've created at least a test
user account for yourself, choose File then quit.
Step 6. Connect a Thin-Client to the
TS
Now you're ready to connect a terminal
to the server. Choose any PC that is within your network subnet.
Reboot the PC and enter the BIOS setup.
With some PCs this requires you to press the F2 key before Windows
or another OS loads up. In some other systems and laptops it is the
F12 key that allows you to choose boot device.
You simply need to get access to the PC
prior to it loading an OS and select a Network boot rather than a
hard disk boot. Sometimes you need to also designate the Protocol,
which should be PXE.
Now allow the PC to boot from the
Network. If all works correctly, within a few seconds you should see
the PC begin initializing a Linux virtual desktop and then the Fedora login screen.
Now log in using your test account name
and password.
You are now in and using the TS as a
thin-client. That's all there is to it... Enjoy!
Appendix A. Connecting to the Internet
As you recall, we installed two network
cards. One was exclusively to be used for all internal networking
and the second for external networking.
You may connect a DSL or other
broadband connection to the second ethernet device. However, before
you do, please keep in mind several things. Depending on your business
situation, you may not have a firewall or other security
settings protecting such a connection. It's vital you setup a firewall. Although the K-12LTSP comes with many pre-configured
firewall and security settings, it is best to get some more insight
prior to connecting to an external Internet source. I recommend you
atleast review these two articles:
Setting up a business firewall
Using Linux with DSL
TIP: Never connect any business server to
an external Internet source without some form of security model in
place.
Appendix B. Getting Access to other
Windows PCs from the TS
You can use the very powerful Windows
to Linux networking tool called SAMBA to perform file-sharing on an
existing network.
The details for how to setup and run
SAMBA are included in my article: Integrating Linux in a Windows
Network with SAMBA.
Mark Rais, author of Linux for the Rest of Us, dedicates his time and energy promoting OpenSource technology, especially among the
poor and where a technology divide exists. He serves as senior editor for reallylinux.com and as a technology consultant to those interested in switching to Linux.
Linux is a registered trademark of Linus Torvalds. Microsoft, Windows, Microsoft Office are the registered trademarks or trademarks of Microsoft Corporation in the U.S and internationally. ALL other service marks, trademarks, and registered trademarks are owned by their respective companies. The information on this web page is published explicitly as opinions and is not to be deemed factual or verified information. For factual information refer to more than one source and judge for yourself.
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