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Processors Toolkit

Get users diskless with Linux thin client

Vincent Danen Tech Republic

Published: 02 Apr 2003 09:57 BST

Thanks to new thin client technology, the old dumb terminals aren't such a dumb idea after all. Any way to extend the lifespan of existing hardware is a smart move these days, and on the Linux front, you can give life to even the slowest of hardware with the Linux Terminal Server Project (LTSP). With this amazing thin client solution, you can have your end users working at diskless terminals with any graphical applications you choose.

I am going to show you how to get LTSP up and running so you can regain more control over your enterprise-computing environment.

Installing LTSP
Installing LTSP is simple. From the LTSP Web site, you download the LTSP components necessary for a complete installation. You can choose to download RPM, DEB, or source tarballs. You will need these four basic components:

lts_core
lts_kernel
lts_x_core
lts_x_fonts

In addition, you will need to run a DHCP server and a Trivial File Transport Protocol (tFTP) server on the Linux system you will be using as the LTSP host.

Additional info
For more information on setting up a DHCP server on Linux, see "Installing a DHCP server under Linux." You can learn more about the tFTP protocol by running the command man tftp.

Finally, for each workstation you will be using as a thin terminal client, you'll need to generate a boot floppy. You have two choices: You can modify the bootrom on the network card, which may require special equipment, or you can use a floppy disk to boot. Since floppy drives are inexpensive, and this method is easiest, I'll use a boot floppy in this article.

Go to the ROM-o-matic site to select the network card your workstation uses. This demonstration uses a workstation with a D-Link DFE-530TX card. This setup uses the rtl8139 chipset, so the appropriate network card ROM is the rtl8139. Make sure that the ROM output is set to bootable floppy and then click Get ROM.

To generate the boot floppy, insert a blank floppy and use the dd if=eb-5.0.4-rt18139.lzdsk of=/dev/fd0 command (changing the filename to match the file you downloaded).

Hardware compatibility
If you can't determine what driver to use, you can find out from the Red Hat site (for Red Hat systems), from the Mandrake Linux site (for Mandrake Linux systems), or by doing a search on Etherboot, which lists a lot of network card manufacturers and tries to correlate network card models with the appropriate kernel driver.

Insert the newly generated floppy into your workstation and boot from it, making sure you've set the BIOS to boot from floppy. The ROM should find your network card and report the MAC address, or hardware Ethernet address, of the card.

Configuring the LTSP Server
Before you can configure the server, be sure that both DHCP and tFTP daemons are installed. (On all recent distributions, these are included with a standard server installation and can be checked with the commands rpm -q dhcp and rpm -q tftp.) Install the LTSP files downloaded from the LTSP Web site using RPM, DEB, or tarballs (whichever your system requires). If you downloaded source files, you will need to compile the software first.

Nonstandard installation directory
If installing via RPM, make note that RPM will install LTSP into the /opt/ltsp directory (as opposed to the standard /usr/bin or /usr/sbin).

Configuring your system to run the LTSP server involves executing a script on the server called ltsp_initialize in the /opt/ltsp/templates directory. This will modify your system configuration files to allow the client system to access the server. The ltsp_initialize script will modify your Gnome Display Manager (GDM), KDE Display Manager (KDM), or X Display Manager (XDM) configuration files (depending on which you employ) to allow for remote client access to your chosen display manager and logon. The ltsp_initialize script will also modify your /etc/exports file to export the LTSP root and swap file systems, create an example /etc/dhcpd.conf file, and enable tFTP in inetd.

Once ltsp_initialize is complete, double-check a few files to ensure that things are correctly configured, as LTSP makes no guesses about network setup and instead defaults to using a 192.168.0.0 network. For example, you will want to modify your /etc/exports to look like that in Listing A if you are using a 10.0.0.0 network.