View source for Cool Solution - XenApp/XenDesktop on Thinclient with only 1GB Flash

{{Version|UCC=1.0}} 
{{Cool Solutions Disclaimer}}

= Introduction =

Thin Clients may have smaller storage devices (i.e. Compact Flash or onboard Flash) than the default 1,2G of the UCC default image.

This is an example for a thin client image for 1GB Flash supporting XenApp. 

The configuration file, tested on a HP t5745(1GB), can be found at the bottom of this article.

== Software packages required ==
Here we are going to create a small UCC Thin Client image targeting full Citrix support, tested in a HP t5745 with 1GB flash storage.

In a typical deployment, some of our customers often require these features in order of priority:

* XenApp Session (+Firefox), including german localisation
* Typical ressoures: Sound, Flash, HDX
* if possible special enhancements: truecrypt
* if also possible RDP session as a fallback

== General procedure ==

For this we are going to need two diferent approaches, first we will use the ucc-image utility to build an image with an edited configuration file, and second we will manually install the packages left from the previous step.

= Step 1 - Configuration File  =

This file is based on the official file for a thin client 

 /usr/share/doc/ucc-image-toolkit/example/ucc-thinclient.cfg

Please read [http://docs.univention.de/ucc-manual-1.0.html#imagegen:chapter UCC Manual Generation of adapted images].&nbsp; 

The official images are also explained in [[Building_UCC_images]]

Another configuration file to generate a <1GB image [[Configuration_file_for_a_reduced-sized_thin_client]]

The image size is set at 794MB: 

 # Image size in GB
 size: 0.794

== Important packages  ==

A graphical system is still installed, but without desktop manager: 

packages_no_recommends: 

 univention-lightdm (Integration of lightDM login manager into UCC)
 indicator-session (Session management, status and user switching)
 indicator-power (Power state)

X window system (and input drivers)<br> 

 xserver-xorg 
 xserver-xorg-input-mouse
 xserver-xorg-input-kbd

Drivers for some typical video card families 

 xserver-xorg-video-ati
 xserver-xorg-video-intel
 xserver-xorg-video-vesa
 xserver-xorg-video-nouveau
 xserver-xorg-video-sis

Audio server: 

 pulseaudio

Tools: (no sessions are installed in this step)

 openssh-server (Remote secure shell (SSH) server)
 language-pack-de
 firefox-locale-de
 ntpdate (client for NTP time servers)
 libmotif4
 curl
 nspluginwrapper
 libcap2

UCC Cool-Solutions
 univention-ucc-status

Integration with the UCC domain, always required: 

 univention-ucc-theme (Univention theme)
 univention-corporate-client (Metapackage for client systems)

These are also essential:

 # These packages will be installed 
 packages:
 # Kernel
 linux-image-generic (Linux kernel image)
 # Grub
 univention-ucc-grub (Grub2 configuration)

== Repositories ==

If you want to include packages from the UCC Cool-Solutions Repository (e.g. univention-ucc-status from above), you need to [[Howtos_UCS_3.1#Integrate_the_Cool_Solutions_Repository_in_UCC|integrate the Repository]] in the image:

 sources_list:
  [...]
  deb http://ucc.software-univention.de/unmaintained/component/ ucc-coolsolutions/all/
  deb http://ucc.software-univention.de/unmaintained/component/ ucc-coolsolutions/$(ARCH)/

You also need to include multiverse for some packages XenApp and Citrix Receiver require:

 # Use multiverse repository?
 multiverse: true

== Name ==

Don't forget to rename your image:

 # Name of output image
 name: ucc-%(version)s-thinclient-image-1G.img

== Partition scheme  ==

/boot is set to 45MB. This is usually enough for one kernel, meaning that kernel updates should be performed by generating the image once again.<br> 

 partition2_name: boot
 partition2_size: 45
 partition2_fs: ext4
 partition2_mountpoint: /boot

<br> The slash partition (/) will take all the available space. 

 partition3_name: root
 partition3_size: expand
 partition3_fs: ext4
 partition3_mountpoint: /

The GPT would start at 2MB for alignment, and it will use 10MB of space. No "swap" partition is considered.

Now, after calling 
 ucc-image -c thinclient-image-1G.cfg 
we will get the initial image, somewhere in the /tmp/ directory, e.g. /tmp/tmprUgkUj/ucc-1.0-rev2-thinclient-image-1G.img
The precise path will be shown at the end of the image creation process. Alternatively, you can specifiy the target directory using the -t switch.

= Manual installation of extra packages =

The idea is to first free some space used by apt-get and then temporarily mount additional disks so we get enough cache for packages.

That is to delete the cache of packages in var/cache/apt and var/lib/apt

First let us mount the image in /mnt/img/
 mkdir /mnt/img
 mount -o loop /tmp/tmprUgkUj/ucc-1.0-rev2-thinclient-image-1G.img /mnt/img/
and free some space:
 chroot /mnt/img/
 apt-get clean
should free var/cache/apt/archives/ and the lists we can delete manually:
 rm /var/lib/apt/lists/*
there should remain a 'partial' directory in there
 exit

Second, let us create and mount the new filesystems
 dd if=/dev/zero of=/tmp/cache-apt bs=1M count=500 && mkfs.ext4 -F /tmp/cache-apt
 dd if=/dev/zero of=/tmp/apt-lists bs=1M count=500 && mkfs.ext4 -F /tmp/apt-lists
Now they can be mounted
 mount -o loop /tmp/cache-apt /mnt/img/var/cache/apt/
 mkdir -p /mnt/img/var/cache/apt/archives/partial
 mount -o loop /tmp/apt-lists /mnt/img/var/lib/apt/lists/
 mkdir /mnt/img/var/lib/apt/lists/partial

The 'Citrix Receiver for Linux' and the 'USB Support Package' can  be downloaded from [https://www.citrix.com/downloads/citrix-receiver/linux/ Here]
Please copy them into the cache directory
 cp icaclient-12.1.0_i386.deb /mnt/img/var/cache/apt/
 cp ctxusb-2.2.0_i386.deb /mnt/img/var/cache/apt/

with all ready, we can go into the image
 chroot /mnt/img/
Once inside we can install xenapp session (~200MB in this case)
 apt-get update
 apt-get install --no-install-recommends univention-ucc-session-xenapp
Install the receiver and the USB support (the system outside the chroot should also be i386. [https://forge.univention.org/bugzilla/show_bug.cgi?id=31787 Bug])
 dpkg -i /var/cache/apt/icaclient-12.1.0_i386.deb
 dpkg -i /var/cache/apt/ctxusb-2.2.0_i386.deb

Create symbolic links for the browser plugin (the icaclient package itself fails to create them in this scenario):
 mkdir -p /usr/lib/mozilla/plugins/
 ln -s /opt/Citrix/ICAClient/npica.so /usr/lib/mozilla/plugins/

Now the image is complete, so we exit and unmount:
 apt-get clean
 sync
 exit
 
 umount /mnt/img/var/cache/apt/
 umount /mnt/img/var/lib/apt/lists/
 umount /mnt/img

Thanks to the 50MB buffer that the image has, other utilities as flash player can be added later, once the client is rolled out.

= Known Issues =

* client shutdown fails, the client needs to be powered off using the power button

= Further Info =

*[https://forge.univention.org/bugzilla/attachment.cgi?id=5362 794MB image configuration file]

*[[Configuration_file_for_a_reduced-sized_thin_client]]

*[[Building_UCC_images]]

*[http://docs.univention.de/ucc-manual-1.0.html#imagegen:chapter UCC 1.0 Manual - Chapter 8 Generation of adapted UCC images ]

*[http://wiki.univention.de/index.php?title=UCC-Quickstart_1.0 UCC 1.0 Quickstart]

*[http://wiki.univention.de/index.php?title=Univention_Corporate_Client UCC Wiki]

*[http://forum.univention.de/viewforum.php?f=65 Start a topic in the EN forum]