User Tools

Site Tools


doc:howto:tce

This is an old revision of the document!


X2Go-ThinClientEditon (TCE, TCE-NG, TCE-New)

History and Rationale

During the time of Debian Wheezy being Debian's stable release, we started developing a new ThinClientEdition (TCE) - one that is based on Debian-Live and thus does no longer rely on NFS. Instead, the entire image is loaded into the RAM of the ThinClient machine.

The disadvantage is that your ThinClient now needs at least 1 GB of RAM (see below).

However, the huge advantage is that there no longer is a need for any high-availibility setup concerning NFS. All you need is an HTTP or FTP server with a dedicated IP, if you want to use netbooting. It is also possible to deploy the image to the ThinClient's local storage, if present, and have it update in the background. Also, making changes/updating the NFS-based TCE was rather finicky - with the current TCE, you build and deploy a new image every time you make a change, and you can test it on a single client without interrupting your production environment.

We've also received reports that the old NFS-based TCE wouldn't work with Jessie, or at least it was very hard to get it to work. Our current TCE works just fine with Jessie, and we expect it to work in Stretch and hopefully in Buster (Stretch+1) as well. The one catch is that the live-build package in Debian/the Debian-Live project is currently looking for a new maintainer - so there is a slim chance that live-build might be removed from Debian Buster, especially if no new maintainer steps up and the live-build replacement that is currently in the works contains all the required functionality of live-build by then.

ThinClient prerequisites for all variants

  • At least 1 GB of RAM
  • At least an i586-compatible CPU
  • Capability to boot via PXE or sufficient local storage (expect 250-450 MB, depending on what you decide to include)
  • A graphics card and input devices (Keyboard, Mouse/Trackball/Touchpad/Trackpoint/Touchscreen, …) that are supported by the stock Debian X Server

Build system prerequisites for all variants

  • You need a Debian Jessie system to build the image. (Other distributions based on Debian might work, but this is untested.)
  • We suggest using a 64-Bit system, though it should be possible to use a 32-Bit system if you don't want to build a 64-Bit ThinClient image.
  • We suggest leaving at least 4 GB of free disk space so the build won't abort due to insufficient disk space.
  • Make sure your package list is up to date by running:
    sudo apt-get update 
  • Install the required packages by running:
    sudo apt-get install git-core live-build live-config-doc live-manual-html live-boot-doc
  • export the following variables:
    # Select ONE of the following LBX2GO_ARCH lines and comment out the others 
    # (feel free to use long or short options)
    # for 64-Bit builds, use:
    # export LBX2GO_ARCH='-a amd64 -k amd64' 
    # 32-Bit, larger memory footprint, but faster performance on i686 and newer
    # export LBX2GO_ARCH='-a i386 -k 686-pae'
    # 32-Bit, smallest memory footprint
    export LBX2GO_ARCH='--architectures i386 --linux-flavours 586' 
    
    # These options are meant to reduce the image size.
    # Feel free to adapt them after consulting "man lb_config"
    export LBX2GO_SPACE='--checksums none --apt-indices none --cache false \
                         --apt-recommends false --win32-loader false --memtest none\
                         --firmware-binary false --initramfs-compression lzma'
    
    # These are default values that should not require tuning
    export LBX2GO_DEFAULTS='--initsystem sysvinit --security true --updates true \
                            --firmware-chroot true --backports true
                            --archive-areas "main contrib non-free"'

Netbooting

Prerequisites

  • You need an existing DHCP/PXE/TFTP setup with the usual pxelinux.0/pxelinux.cfg boot and configuration files, and a directory where kernel and initrd can be stored. This is not covered here, though we might add a separate howto for that some time later on.
  • You will also need an HTTP/FTP server with a dedicated IP (no name-based virtual hosts) for the squashfs image.
    • This image cannot be deployed via TFTP as it is too large - some TFTP servers refuse to serve files lager than 32MB, and some TFTP clients have problems with that as well.
    • Also, even if you have a TFTP server/client combination that handles files larger than 32 MB, it will still be waaaay slower than the HTTP/FTP transfer.

Building your own netbootable X2Go-TCE image

Starting the build

Change to a directory where you want to save your builds, and run the following commands:

LBX2GO_IMAGETYPE='netboot'
LBX2GO_CONFIG='http://git-server-and-project::branch'

# This will create a timestamped subdirectory for the build
DIR=./live-build-x2go-$(date +"%Y%m%d%H%M%S") 
mkdir -p $DIR
cd $DIR

# Select ONE of the following LBX2GO_ARCH lines and comment out the others 
# (feel free to use long or short options)
# for 64-Bit builds, use:
# LBX2GO_ARCH='-a amd64 -k amd64' 
# 32-Bit, larger memory footprint, but faster performance on i686 and newer
# LBX2GO_ARCH='-a i386 -k 686-pae'
# 32-Bit, smallest memory footprint
LBX2GO_ARCH='--architectures i386 --linux-flavours 586' 

# These options are meant to reduce the image size.
# Feel free to adapt them after consulting "man lb_config"
LBX2GO_SPACE='--checksums none --apt-indices none --cache false --memtest none \
--apt-recommends false --win32-loader false --firmware-binary false \
--initramfs-compression lzma'

LBX2GO_DEFAULTS='--archive-areas "main contrib non-free" --updates true \
--firmware-chroot true --backports true --security true --initsystem sysvinit'

lb config $LBX2GO_ARCH $LBX2GO_SPACE $LBX2GO_DEFAULTS \
--config $LBX2GO_CONFIG --binary-images $LBX2GO_IMAGETYPE
lb build
lb clean # optional command to clean up afterwards -> saves some space
doc/howto/tce.1481750053.txt.gz · Last modified: 2016/12/14 21:14 by stefanbaur