Thin client configuration

Fine-tuning thin client configuration

Usually, thin clients on an Edubuntu thin client network should work fine out of the box. Occasionally, you would want to fine-tune settings on a client, or alter the settings slightly, either to increase performance, compatibility, or to enable or disable certain features.

Configuration file

Thin client configuration settings are stored in a file called "lts.conf". It has a strange location, since it has to be accessable to the clients while they boot up. This file is located at "/opt/ltsp/(arch)/etc/lts.conf". Replace (arch) with your architechture, typically "i386".

To edit this file, log in as a user with administration rights (usually the first user created). Once logged on, press ALT+F2, which will activate a run dialog, then type:
gksudo "gedit /opt/ltsp/i386/etc/lts.conf"
and press ENTER.

You will then be prompted by a password dialog, enter your user password here, and press ENTER. On a default installation, this file doesn't exist, so you will be presented with an empty text file.

Sections of lts.conf file

The lts.conf file essentially has two types of entries, the default section, which contains settings that applies to all thin clients, and per-thin-client settings, which only applies to thin clients that are the exceptions to the default thin client.

Typical lts.conf file

Example of a simple lts.conf file:

[default]
  SOUND = true

[00:08:A1:55:F1:A3]
  XSERVER = s3
  SOUND = false

In the above example, it states that sound should be enabled for all the thin clients. It also says that one thin client should use an S3 display driver, and should have sound disabled.

The number that is used to identify the thin client (00:08:A1:55:F1:A3) is called a MAC address. You will usually see this on the thin client as it boots up by the network card software. If it flashes by too fast, you can usually make it display longer by unplugging the network card.

Configuration tags

Above, we used the SOUND tag, which sets whether or not sound should be enabled on the thin client. The XSERVER tag specifies which display driver a thin client should use.

There are many tags which allows you to control the settings of a thin client:

  • XSERVER: Display driver setting. Values are: ati, auto, cirrus, cyrix, fbdev, i128, i740, i810, mga, neomagic, nv, r128, radeon, rendition, s3, s3virge, savage, siliconmotion, is, tdfx, tga, trident, tseng, vesa, and vga. If you get stuck, you can use a vesa driver. This is a slow, generic driver, but is generally a good choice as a failsafe driver, since it works on most display cards. auto is the recommended value. It will auto-detect the thin client's display driver, and is the default value if it's not specified in lts.conf
  • X_COLOR_DEPTH: Sets the color depth of the thin client. Values are: 8, 15, 16, 24 and 32. 8 bit color will give you bad image quality, but good performance, while 32 bit colour will give you poor performance. 16 bit colour is recommended.
  • SYSLOG_HOST: Specifies the server address where thin client syslogs should be stored. The value should be an I.P. address of the syslog server, such as 192.168.0.254. If unset, the thin client won't use a syslog server.
  • X_MOUSE_PROTOCOL and X_MOUSE_DEVICE: These settings are only needed to specify the use of serial mice, since all other pointing devices should be auto-detected. The value for X_MOUSE_PROTOCOL for a serial device is 'microsoft', while the X_MOUSE_DEVICE values are /dev/ttyS0 (com1 / first serial port) and /dev/ttyS1 (com2 / second serial port).
  • SOUND: Specifies whether sound is enabled or not. Values are: true, false.
  • NETWORK_COMPRESSION: Specifies whether network compression should be enabled or not. Values are: true, false.
  • XKBMODEL: Specifies keyboard layout. Values include: us, de.