Linux Slimstation

by Gerard Heijnen

Point of Origin

Running an environment with more then 50 terminals, it was a challenge to see if we can reduce the costs of hardware, software and power consumption.
We also like to reduce the possibility of manipulating the workstations by users.
Impressed by the options Linux can give you we came across the site of Thinstation and taylor made the idea for our purposes.

The Objective

We already use Terminal Server access for a large group of users to connect to network files and mail. If you build these servers in a VMware environment the costs for server equipment can be reduced as well.
Printers on these servers are installed as local IP printers, this keeps the servers clean of any traces of sharing, also file and printer sharing is not needed on the clients, this avoid another problem with spreading viruses.



In the search for disk less stations we came across the models below, but old P133 models will do for this purpose.

Diskless station

Diskless station

Left model eBOX-2300 (200Mhz), right model eBOX-3800 (800Mhz).
We tested both models, the eBOX-2300 can be mounted on the back of a TFT panel, which will come in handy if space is an issue. Also it will be interesting for kiosk applications.
In spite of all the options (USB,CF-card,space for internal HD) we found the processor power limited for our deployment.
Model 3800 is an interesting alternative, it has enough power and when ordered with a DOM module, suits our needs.


The benefits of disk less stations:

* - Reduce TCO, easy to control
* - Open source software (no OS costs for terminal stations)
* - "In house design" (helpdesk always available)
* - Can not be manipulated by user
* - Power consumption < 20 Watts (PC > 150Watt)
* - Disk less, (no rotating elements)
* - If lost, no important files missing
* - Easy to deploy on remote stations
* - Stations can be remotely accessed by admin
* - Boots in 40 Seconds

Diskless station

Diskless station

Two screenshots of the "Maintenance-screen" of release RC1


SETUP:

The setup consists of a FAT16 configured DOM (Disk On Module) containing an image file (< 8Mb).
During the boot process, the device gets an IP address and looks for a HTTP (intranet) server.
When the HTTP server is found, it checks the host file for it's host name and user options, confirms the IP address again (using the correct host name) and loads the network file with general settings.
If there are new boot/image files available, the system will download them now. (MD5SUM checked).
Depending on the user options, it will startup the X-server in the requested mode.

Presently we are running more then 55 devices in a production environment with positive results.

Matrox G550

CSP


The MATROX G550 Video card, contains a LFH60 connector.
Besides the adapter cable, a LP (low-profile) & HP (high-profile)
bracket are included in the package.

A few former workstations have been equipped with this Matrox dual-head video card and running the same software Using "Icewm" as a desktop manager, a 4 dual screen environment is available to the user.


Matrox G550


The primary setup can be ideal for "Internet Cafe" use.
The user access to the "Slimstation" is restricted and if necessary, an image can be restored in less then 2 minutes.


HOW IT WORKS:

As stated previously, we used Thinstation as the core application. To reduce network traffic, we decided to use an inside DOM (or hard disk) for boot purposes. An Intranet server is used as a host for the config files needed during boot.
The whole boot process is shown below and exists of two loops, a "normal" and a "recovery" process.


flow


Included are a few "fail safe" options. So is it possible to change the default configuration server by USB during the recovery process.
When for some reason the configuration server is down during the boot process, the config files are available on hard disk as well.
During boot, the system will detect new firmware available and download it (MD5SUM) checked.


MANAGING:

The systems are managed by a WEB interface, this (PHP) application controls the configuration of the devices and monitors the connected clients.


The snapshot below shows an overview of the connected clients.

LEGEND:
* - Client = DNS name of client
* - IP = Present IP address (Clicking on it, starts telnet session)
* - Image = Firmware image on DOM module
* - Drv. = Video driver in use
* - Video Card = Video hardware detected
* - Processor = Processor insight with clock frequency detected

ctlpanel

Gerard
7 July 2009

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