Pre-up and postup scripts are scripts which are run before and after release updates (e.g., for post-processing the update, for example by uninstalling obsolete packages). As of UCS 3.2, these scripts are cryptographically signed to prevent unauthorized modification. During the update and when mirroring the repository these signatures are checked. If they're invalid or missing, the action is aborted.

If a repository server is operated with UCS 3.1-x, it should be updated to UCS 3.2 before additional systems can be updated to UCS 3.2-1 or newer.

If it is not possible to update the repository server, the signature files must be downloaded manually:

LOCAL_DIR="/var/lib//univention-repository/mirror"
SERVER="http://updates.software-univention.de"
for release in 3.2-0 3.2-1 3.2-2; do
	for script in preup postup; do
		file="3.2/maintained/$release/all/$script.sh.gpg"
		wget -O "$LOCAL_DIR/$file" "$SERVER/$file"
	done
done

Alternatively, it is also possible to disable the signature checks, which can be a security risk. For the repository server this can be done by setting the Univention Configuration Registry variable repository/mirror/verify to false. For the update the Univention Configuration Registry variable repository/online/verify must be set to false on all systems.

Anonymous usage statistics on the use of the Univention Management Console are collected when using the free for personal use version of UCS (which is generally used for evaluating UCS). The modules opened are logged in an instance of the web traffic analysis tool Piwik. This makes it possible for Univention to tailor the development of the Univention Management Console better to customer needs and carry out usability improvements.

This logging is only performed when the free-for-personal-use license is used. The license status can be verified by clicking on the cog symbol in the top righthand corner of the Univention Management Console and selecting License information. If Free for personal use edition is listed under License type, this version is in use. When a regular UCS license is used, no usage statistics are collected.

Indendepent of the licence used, the statistics generation can be deactivated by setting the Univention Configuration Registry variable umc/web/piwik to false.

In addition to the standard installation DVD there is also a medium with support for the Unified Extensible Firmware Interface standard (UEFI) available for the amd64 architecture.

It must be used instead of the standard DVD on systems which only support a UEFI boot.

Webkit, Konqueror and QtWebkit are shipped in the maintained branch of the UCS repository, but not covered with security support. Webkit is primarily used for displaying HTML help pages etc. Firefox should be used as the web browser.

Univention Management Console uses numerous JavaScript and CSS functions to display the web interface. Cookies need to be permitted in the browser. The following browsers are recommended:

Users with older browsers may experience display or performance problems.

Some Active Directory functions are currently not available in Samba 4:

Further information can be found in Chapter 8 of the [ucs-handbuch].

During the installation of UCS in the virtualization solution VirtualBox, a VirtualBox bug may appear which has been corrected in version 4.2: if UCS has been successfully installed and the DVD is still in the disk drive, the installation DVD offers the option Boot from first harddisk partition. If you select this option, VirtualBox freezes.

For Linux distributions which still use Virtualbox 4.0 or 4.1, either the installation DVD should be removed from the drive settings of the VirtualBox VM or F12 pressed when starting the virtual instance and the hard drive selected as a boot partition as a workaround before starting the UCS VM. UCS will then start successfully.

When UCS is installed in the virtualization solution Citrix XenServer 6.0 - 6.2, the GRUB menu of the Univention installer is not shown with the Cirrus graphics card emulated as standard. The Univention Installer can be started directly by pressing the ENTER key; alternatively, the installation starts automatically after sixty seconds. The Univention Installer which then starts is displayed as normal.

To display GRUB correctly, the graphics card emulated by XenServer can be reconfigured. This is done by logging on to the XenServer system as the root user. Firstly, the xe vm-list command is used to determine the UUID of the virtual machine. The following command is then used to reconfigure the emulated graphics card to VGA:

xe vm-param-set uuid=UUIDVM platform:vga=std

There are two basic procedures for migrating Samba 3 to Samba 4:

Both procedures are documented in detail in the Univention Wiki: http://wiki.univention.de/index.php?title=Migration_from_Samba_3_to_Samba_4.

If the Xen hypervisor is used and the memory limit for the Dom0 has been configured using the Univention Configuration Registry-Variable grub/xenhopt, the value should be updated to include the ,max: part as well. See the http://wiki.univention.de/index.php?title=UVMM_Quickstart-3.1/en#Configuring_the_Dom0 for details.