Userful MultiSeat Linux™ Release Notes

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Copyright © 2015 Userful Corporation. All rights reserved.
(Updated 2015.09.28)


DisplayLink® is a registered trademark of DisplayLink Corporation.

MCT™ is a trademark of Magic Control Technology Corporation.

SMSC® is a registered trademark of Standard Microsystems Corporation.

EST® is a registered trademark of Elite Silicon Technology.


Userful MultiSeat™ is software that extends Linux to support several fully independent and concurrent workstations using a single computer box. This is accomplished by adding video devices (either video cards, USB multiseat devices or USB-over-LAN multiseat devices), keyboards and mice to a single PC system and installing Userful's software.

This software is available as:

  1. Userful MultiSeat: A stand-alone software package compatible with Ubuntu/Edubuntu.
  2. Userful MultiSeat Linux : Bundled with Edubuntu and other open-source software, with a focus on software for the educational sector.


Userful MultiSeat Linux is a software bundle available as a DVD ISO that features:

Available Versions of Userful MultiSeat Feature:

Userful MultiSeat™ v4.0 provides:

  • A standard Linux software package that extends the Linux operating system to support several independent and concurrent workstations (depending on hardware) using a single PC.
  • MultiSeat with USB: Works with USB multiseat devices using either DisplayLink or MCT USB multiseat chipsets.
    • Although thorough testing for this release has been limited to a few specific devices, other devices are known to work. We are also constantly testing more devices for compatibility.

Userful MultiSeat™ v4.1 expands on the Userful MultiSeat experience, providing all the features of version 4.0 plus:

  • MultiSeat with Video Cards: Add extra stations with tested and supported video cards.
  • An improved user experience and better handling of storage devices.
  • Enhanced system stability.

Userful MultiSeat™ v5.0 provides:

  • MultiSeat with USB-over-LAN Devices: Support for USB-over-LAN stations, USB or video card multiseat configurations.
  • Automatic device assignment to make system setup quicker and easier.
  • User-interface improvements to support new functionality.

License Agreement

This product includes commercial software that is licensed, not sold, and is governed by an End User License Agreement (EULA). By installing, copying or using this software you acknowledge that you have read and understand this Agreement, and agree to be bound by this EULA's terms and conditions. You can review the terms of this EULA either by visiting the online copy of the EULA or by consulting the Userful-EULA.txt file included with your download

Trial Version

Userful MultiSeat will operate as a trial version until you purchase an appropriate license for your Userful system. You may purchase a multi-station license from your Userful representative or from – see the Licensing section of the User Guide for details.

Limitations of Trial Version: The Userful MultiSeat trial software supports is fully functional, but will display a brief license reminder on all attached screens every 10 minutes or so.


Userful MultiSeat is fully translated into:

  • English (en)
  • French (fr)
  • Italian (it)
  • German (de)
  • Spanish (es)
  • Brazilian Portuguese (pt_BR)
  • Russian (ru)
  • Turkish (tr)
  • Japanese (ja)
  • Traditional Chinese (zh_TW)
  • Simplified Chinese (zh_CN)
  • Korean (ko)

The language selected must be specifically "Brazilian Portuguese"; if simply "Portuguese" is selected as a system or session language, then all Userful MultiSeat user interface strings will be in English.

In Userful MultiSeat v4.0, these fonts may not display correctly (that is, boxes may appear instead of characters). For a workaround please see the Userful MultiSeat known issues.

Minimum PC Specifications

As with any multiseat computer configuration, higher performance systems can support more seats with better performance. The following are the minimum system requirements for Userful MultiSeat.

For up to 6 stations:

  • Dual Core Processor
  • 2GB RAM
  • 1 high-speed USB controller interface

For up to 11 stations

  • Quad Core Processor
  • 4GB RAM
  • 2 high-speed USB controller interfaces

For 11-20 stations:

  • Quad Core Processor
  • 8 GB RAM minimum
  • 2 high-speed USB controller interfaces

For 20+ stations (USB-over-LAN only):

  • Quad Core Processor -- Xeon or i7 class
  • 8 GB RAM minimum
  • 2 high-speed USB controller interfaces

For Ethernet zero-client/USB-over-LAN stations, PCs must have a non-wireless network card.

Please Note: PCI-E (PCI Express) USB expansion cards are not supported with Userful MultiSeat.

Network Specifications for USB-over-LAN

Please refer to the USB-over-LAN (Network) MultiSeat Guidelines for more details regarding ethernet zero-client/network station setup.

Userful recommends the following network hardware (exact details will depend on the number of stations to be set up and the desired physical configuration).

  1. Good quality network cable for all connections is important. Cable should be at least Cat-5e.
  2. Ethernet zero-client devices should not be connected to the computer directly. The host computer should connect to a switch through a gigabit-capable port. USB-over-LAN devices should connect to this switch, or to other switches networked with the switch that is connected to the host.
  3. More than one switch can be used - and in fact may be desired, depending on the physical configuration of the room or rooms.
  4. A good quality router is needed to act as a DHCP server to give IP addresses to the ethernet zero-client devices, unless using a static IP address for each device. PLEASE NOTE: Don't place a router between the host PC and any Ethernet devices. The router may introduce small delays that can cause system instability.
    • Depending on the size and complexity of the installation, you may want to isolate the network station LAN from the existing network infrastructure using a router or a VLAN.

Please Note: Even if using static IP settings for network devices, a router is still recommended for two reasons:

  1. A DHCP server (which is provided by a router) is needed to initially connect to network stations, in order to configure settings (including static IP addresses, and
  2. A router serves to isolate the rest of the network from the (potentially) large volume of traffic between host and stations.

Please Note: If connecting to the internet through an ASDL modem with a static IP address, it is still necessary to use a router to act as a DHCP server. For more information, please see the ethernet zero-client How-To.

Connection Speed/Capacity Requirements


Different parts of an Ethernet Zero-Client MultiSeat LAN have different connection speed minimum requirements. When planning your deployment, please ensure that routers and switches have the required number of gigabit ports, as described below:

  • The required speed of the connection from the router (which is required to provide a DHCP server, and provides a connection to the outside network or internet) to the main switch depends on the speed of the uplink to the internet/outside network.
    • If the uplink speed is limited to 10 Mbps, then a 10/100 Mbps connection is sufficient between the router and main switch.
    • If the uplink speed is faster than 10 Mbps, then a gigabit connection is required.
  • The connection between the host PC and the main switch MUST be gigabit capacity.
  • The connection between two switches must be gigabit capacity.
  • The connection to a single network device can be 10/100 Mbps.

Number of Users/Stations Supported

Even with single-user computer systems (i.e./ a stand-alone desktop computer or personal laptop), user experience depends on several factors:

  1. The speed and power of the CPU
  2. The available system memory (RAM)
  3. The demands made upon the system by the operating system and applications
  4. The speed and capacity of network connections and hardware

With multi-station computing, these factors influence the maximum user capacity of a given system configuration. The section above outlines the minimum system specifications that can be expected to give a satisfactory user experience under most normal use cases.

Some limitations are imposed by the hardware used to multiply the system:

  • With multiple video cards, deployments are typically limited to 8 additional stations + 1 onboard station (8 + 1) because of a limit on the number of PCI expansion slots available on standard (i.e. not custom or very high-end) motherboards.
  • With USB multiseat devices, each system USB bus can only support 4-5 stations with good performance; thus the practical limit of these systems is 15 additional stations + 1 onboard station. (15 + 1).
  • With USB-over-LAN (also called "network") devices, the system capacity is highly dependent on both usage scenarios and system configuration (including network configuration). Refer to the table below for system capacity guidelines , based upon the minimum PC specifications for more than 20+ stations.

Number of Users Supported
(with Minimum PC Specifications)

Low Usage Scenario

  • Single application per users
  • Low-bandwidth web usage
    • (no flash video)

Medium Usage Scenario

  • 2-3 applications per user
  • Low-bandwidth web usage
    • (no flash video)

High Usage Scenario

  • Several applications per user
  • Medium-bandwidth web usage
    • (a few users with flash video)
  • A few users watching native video (not web-based)

480p Video on All Stations

  • Using Totem or MPlayer
  • Fullscreen

720p Video on All Stations

  • Using Totem or MPlayer
  • Fullscreen

Please Note: The table above is provided as a guideline only. Individual system capacity will vary depending on a number of factors, including network factors.

Userful STRONGLY recommends thoroughly testing a given system and network configuration with anticipated usage scenarios before deployment.

Compatible Video Cards

If Using a Single Video Card

When using USB multiseat devices (all Userful MultiSeat versions) or USB-over-LAN multiseat devices (v5.0 and later), only one video card is used per system. This is called the "onboard" video card and may be integrated into the motherboard or added via PCI expansion slot.

For onboard video only, Userful MultiSeat is compatible with any video card supported by the underlying Linux distribution.

Information on video cards supported by Ubuntu/Edubuntu can be found in the Ubuntu documentation.

Please Note: Only one video output head of motherboards with dual-head radeon graphics is supported. Please see Known Issues for details and a workaround.

If Using Multiple Video Cards

Userful MultiSeat v4.1 and later can use multiple video cards to create extra stations. Below are guidelines for choosing multiple video cards.

Userful MultiSeat requires that only one video card driver be in use in the system. Therefore, some care must be taken choosing host system motherboards (and integrated graphics processing units, or GPUs) and extra video cards for stations.

Any nVIDIA cards supported by Ubuntu/Edubuntu can be used to create a multiseat system (up to a configuration of 4 dual-head cards for 8 additional stations) with Userful MultiSeat 4.1 and later provided that:

  • All video cards used for multiseat are using the same nVIDIA driver version, AND
    • If the onboard/integrated GPU is nVIDIA, that it uses the same driver version as the extra nVIDIA cards; or,
    • If the integrated GPU is NOT nVIDIA (i.e., Intel or ATI), that the onboard video be disabled in the BIOS. Please check system BIOS documentation for information on how to disable onboard graphics.
    • If the system is 32-bit, please see this Known Issue regarding a potential problem with kernel virtual address space.

Please Note: The open-source nVIDIA driver, nouveau, is incompatible with Userful MultiSeat. Unfortunately, the Ubuntu operating system tries to force the use of nouveau driver, which can lead to problems starting stations based on multiple nVIDIA graphics cards.

This issue does not occur with Userful MultiSeat Linux (the install DVD), which has been modified. However, if using stand-alone Userful MultiSeat plus nVIDIA cards as a multiseat solution, it is important to blacklist the nouveau driver so that it is not loaded at startup. For instructions, please see How to Change Boot Options with the GRUB Bootloader.

Please Note: If using NVIDIA with the stand-alone Userful MultiSeat package, the appropriate proprietary driver must be installed. To find the correct driver for the video cards, go to the NVIDIA download center.

If using Userful MultiSeat Linux, the NVIDIA driver version 290.10 is included. A list of video cards supported by that driver version is available from NVIDIA. If your hardware is not supported by the 290.10 driver, the appropriate proprietary driver must be installed.

Using DisplayPort® Video Connections

Some motherboards and/or video cards have DisplayPort connections instead of, or in addition to, VGA or DVI connections.

These devices can work with Userful MultiSeat, but require manual configuration to add the device to the database. For more information and instructions, please see the DisplayPort How-To.

Supported USB Multiseat Devices

Compatible USB-over-LAN Multiseat Devices - for Userful MultiSeat v.5.0

Userful MultiSeat v5.0 (and later) is designed to support USB-over-LAN multiseat devices (using the Elite Silicon® (EST) USB to LAN chipset) with one of the following USB graphics chipsets: DisplayLink®, SMSC®chipsets.

Userful has tested and confirmed that the following devices are supported for the versions of Userful MultiSeat indicated.

Compatible USB Multiseat Devices

To facilitate purchase of hardware compatible with Userful MultiSeat™, specific USB multiseat devices are listed below in colored categories Recommended, Might Work and Known Incompatible.

Recommended USB Multiseat Devices

Userful MultiSeat is designed to support USB multiseat devices using DisplayLink® and SMSC®chipsets, as well as MCT™ devices with the Trigger 1+ chipset.

Userful has tested and confirmed that the following DisplayLink®, SMSC® and MCT™ devices are supported for the versions of Userful MultiSeat indicated.

Please note that the HP t150, Atrust M200/202, GWC DU2600 and ViewSonic VMA10 are supported with Userful Multiseat 4.0-1702 (and later) only, and the HPt200 (using USB connections -- ethernet connection not officially supported in this release) is supported with Userful MultiSeat 4.1-4008 (and later) only.

To verify the version number of your copy of Userful MultiSeat, open the Control Center and go to "Help & Support > About Userful MultiSeat".

If you wish to use these devices and do not have at least Userful Multiseat 4.0-1702, please upgrade your version of Userful MultiSeat by uninstalling the software, downloading the latest Userful MultiSeat from the Userful website, and installing the latest version.

Getting and Installing the SMSC Driver (v.4.1 Only)

The SMSC graphics chipset requires a driver that must be downloaded and installed separately from Userful MultiSeat v4.1. Note: this driver is included with the Userful MultiSeat v5.0 package and does not need to be separately installed.

The driver is provided as a .deb package which can be installed by simply double-clicking on the downloaded file (sudo or superuser privileges are required for installation).

To get the SMSC driver for 32-bit Ubuntu/Edubuntu, click here and save the file to the Userful MultiSeat system:

To get the SMSC driver for 64-bit Ubuntu/Edubuntu, click here and save the file to the Userful MultiSeat system:

USB Multiseat Devices That Might Work

Here are the USB multiseat devices that might work with Userful MultiSeat™. These have been seen to work in some cases with certain configurations, but results have been inconsistent or testing has been limited.

Number of Stations Supported

(USB Stations + 1 Onboard)

Recommended Devices Chipset External Power Supply Required
11 stations
(10 + 1)
Wyse E01 Thin Client MCT
Trigger UV-185CB-128
5 stations
(4 + 1)
Thinnet MiniPoint MCT
3 stations
(2 + 1)
NComputing U170 MCT
(undetermined) IOGear USB 2.0 External VGA Video Card (GUC2020DW6) DisplayLink
(undetermined) MCT USB-DVI Display Adapter MCT
Trigger UV-185CC-176
(undetermined) MCT USB-VGA Display Adapter MCT
Trigger UV-185CC-176
(undetermined) Aluratek USB 2.0 to Dual MONITOR/VGA Adapter MCT
Trigger UV-185CC-176

USB Multiseat Devices That Are Known to be Incompatible

These are devices that are known to have significant issues when used with Userful MultiSeat:

Unsupported Devices Chipset
Tritton SEE2 UV150 USB 2.0 To VGA Ext. Video Card MCT
Trigger UV-105CB-128
Targus Universal Notebook Docking Station with Video ACP50CA MCT
Trigger UV-185CC-176
StarTech USB 2.0 to VGA/DVI Display Adapter Volari V2 PAA0045

Getting Userful MultiSeat Linux 2011

Final release versions of Userful MultiSeat Linux are available as a 32- or 64-bit DVD ISO. Userful MultiSeat Linux 5.0 is only available in 64-bit.

To obtain an install disk:

  1. Download the appropriate disk image (ISO file) and save it to your hard drive.
  2. Confirm that the file downloaded without errors by using a checksum program.
  3. Burn a DVD using the ISO image that you downloaded.

If you are installing 32-bit Userful MultiSeat Linux 2011 v4.0, a custom Userful-patched version of GDM (the Gnome Display Manager) is included. Should you ever need to re-install this package, it can be downloaded from Userful's website (the checksum is here. The Userful-patched GDM file should be saved to the Desktop, and can be installed with the package manager simply by double-clicking the package icon.

Without the custom GDM package, the log-in screen experiences frequent long delays and freezing. The custom-patched GDM is not needed with Userful MultiSeat Linux 2011 v4.1 and later versions.


Note: We recommend installing Userful MultiSeat Linux onto a host PC with no extra connected stations (with other stations connected, the correct mouse may not be recognized). In addition, ensure that at least one monitor is connected to the onboard video card through a VGA cable so that boot screens will be visible.

To start installation from the Userful MultiSeat Linux DVD, simply

  1. Ensure that the BIOS is set to boot from the optical drive (see How To Change Boot Device Priority).
  2. Insert the ISO image DVD into the optical drive.
  3. Restart the computer.
    • There may be a long delay before the initial install screen appears; during this delay users may see boot-like text screens or even error messages. This is not something to be concerned about, and typically the first install screen will appear after fewer than 3 minutes. If after 5 minutes the installation prompt screen has not appeared, there may be an issue with your installation media. Please refer to this How To for troubleshooting tips.
  4. When the first install screen appears, choose "Install Userful MultiSeat Linux".
    • If you already have an operating system installed, you will be asked to choose whether to erase and overwrite the existing OS, or to repartition the hard disk to install Userful MultiSeat Linux alongside your existing OS (creating a dual-boot hard disk).
    • The remainder of the installation process proceeds as with a standard Ubuntu install (please refer to Ubuntu documentation for further information, or see below).
  5. Choose the default language you wish to use for the system.
  6. Select the time zone.
  7. Choose a keyboard layout.
  8. The "Prepare disk space" dialog will appear. If a dual-boot system is desired, choose to "Install them side-by-side, choosing between them each startup."
  9. Enter personal information and choose a password. The user name and password entered at this step will be the administrator user name and password needed to configure the system later. Please take note of it.
  10. As the last step in installation set-up, a "Ready to install" summary screen appears. Review the installation parameters chosen, and click "Install" to proceed.
  11. The Userful MultiSeat packages will automatically be installed during the final steps of Ubuntu installation.
  12. Completion of installation is guided by the Userful MultiSeat install wizard (see the next section for details).
  13. When setup wizard is complete, you will be asked to reboot.
    • The install DVD should automatically eject the disk, and depending on the system configuration, there may be a prompt on the screen to "Remove the disk, close the tray, and click Enter"; remove the disk and press "Enter" to complete the reboot.
    • Important: Occasionally, the system freezes during this reboot process. If this should occur, use the PC power button or reset button to manually reboot the computer.

Please see below for important guidelines for getting started with Userful MultiSeat.

Upgrading Userful MultiSeat

Please Note: To upgrade just the Userful MultiSeat component of Userful MultiSeat Linux, simply download and install the stand-alone Userful MultiSeat package, not the Userful MultiSeat Linux .iso file.

If you determine that you must do a fresh install of all components of Userful MultiSeat Linux -- including the operating system -- be sure to back up all user data and save that backup to another location (that is, do not save the backup onto the Userful MultiSeat Linux system itself).

Existing users of Userful MultiSeat Linux can upgrade or reinstall Userful MultiSeat quickly and easily. Simply:

  1. First, verify the version number of your copy of Userful MultiSeat by opening the Control Center and going to "Help & Support > About Userful MultiSeat".
  2. If you choose to upgrade to a newer release of Userful MultiSeat, download the appropriate package for your Linux distro.
  3. Save the Userful MultiSeat package file to the desktop of a user account with administrative privileges.
  4. Go to the Userful Control Center and turn off Userful MultiSeat.
  5. Double-click on the package that has been saved on the desktop. This will launch the package manager of the Linux distribution, which will first remove the older package, then install the upgraded package. It may be necessary to change permissions on the installation package; please refer to the previous section for instructions.
  6. From the Control Center, turn on Userful MultiSeat.
  7. Reboot the computer.

For more details on the installation process please see the installation section of the complete User's Guide.

Post-Installation Configuration

The Boot Menu

Once Userful MultiSeat Linux is installed, users will see a boot menu during system startup or restart. The boot menu is a list of available Linux kernels and/or, if Userful MultiSeat Linux was installed alongside an existing operating system, a list of available operating systems. Userful MultiSeat Linux will typically be the top option on the list of OS choices. The boot menu entry will say "Ubuntu, with Linux X.X.X.X generic". If ever in doubt about which Linux kernel to choose, Userful MultiSeat Linux will be the one with the latest kernel version number.

Userful MultiSeat Linux creates a rule for the boot menu so that the computer will automatically boot into the last operating system or kernel used by default. This means user intervention (by making a choice at the boot menu) is not required unless changing to a different operating system or kernel. (Note that if another OS is installed after Userful MultiSeat Linux, that operating system will appear at the top of the boot menu, and the special "boot into last-used OS" rule will have been overwritten).

Extra User Accounts

The Userful MultiSeat Linux installation process will automatically create a number of accounts to simplify use in a classroom setting with iTALC.

Note: With Userful MultiSeat Linux 5.0, iTALC is not installed by default; however it can be installed quickly and easily. Please see instructions in How To Use iTALC with Userful MultiSeat.

Specifically, the following user accounts are created:

  • between 15 and 40 student accounts (depending on the version of Userful MultiSeat Linux), with usernames "studentn", and
  • 1 teacher account, with username "teacher01"

Each user will be prompted to enter a password the first time they log in. The exception is the administrative user (the username and password specified during installation).

Please Note: Depending on your particular installlation, the automatically created user account may not be working properly. If you experience any problems with these user accounts, simply delete them and create new user accounts.

If you later wish to change passwords, or need to create other accounts, please refer to this How To about the Users and Groups administration tool (located in System > Administration > Users and Groups).

Please Note: By default, the Ubuntu operating system allows all users to read files and folders in any users "Home" directory. User accounts created during Userful MultiSeat Linux installation have been specially modified to restrict read permissions for other users. Any accounts created after installation will not have these special modified permissions.

To learn how to change permissions for "Home" directories, please refer to these instructions.

Set a Root Password

Ubuntu/Edubuntu does not set a root password by default. Instead, Ubuntu relies on the sudo functionality (see the sudo home page for more information. However, Userful recommends setting a root password in case it is necessary to work in non-graphical mode (for troubleshooting, for example), and to access the Userful Control Center in some circumstances.

To set a root password, on the host computer:

  1. Open a terminal.
  2. Enter the following command:
 sudo passwd root
  1. Enter the sudo password.
  2. Next, enter the new root password. You will be asked to repeat the password.

Update the Operating System

After installing the Userful MultiSeat Linux DVD, the operating system's Update Manager will probably launch so that the installation can be brought up to date with the latest fixes and added features. Please see below, how to update the operating system with Userful MultiSeat installed, for instructions.

The system may be restarted now, or stations may be set up before a reboot. Please see the next section for information on station set-up.

The Control Center

Userful MultiSeat features the Userful Control Center™.

The Control Center features:

  • A system/station status dashboard
  • Individual or system-wide display configuration
  • Individual or system-wide control over station access
  • Software updates, license management and access to help and support.

The Userful Control Center is located under System > Administration > Userful Control Center. A dialog window will appear and the administrator must log in to proceed to the Control Center.

For more information about the Control Center, please see the Userful MultiSeat User Guide.


Userful MultiSeat requires a license key. The unlicensed version has full functionality, but a 'license reminder screen' will appear after the first 20 minutes of use, and every 10 minutes thereafter.

License keys issued for versions of the software older than Userful Multiplier 3.8 will not function with Userful MultiSeat. For new license keys for Userful MultiSeat, either use a Free-2-User license, or contact:

Adding or Removing USB or Network (USB-over-LAN) Stations

To add a station, simply plug in a multiseat device. No reboot is necessary, the station will be ready to use after a brief pause (assuming your license supports that number of stations).

Stations can be removed simply by unplugging the multiseat (even from a running system).

Running 3D Applications

Userful MultiSeat offers 3D software rendering and therefore can run applications that do not require hardware acceleration, such as Google Earth, K3DSurf and KSudoko. Please note that 3D graphics performance improves with more powerful CPUs. For optimal performance, avoid simultaneously running more 3D applications than the number of CPU cores in the host machine (i.e. a quad core CPU is best suited to run a maximum of 4 simultaneous 3D applications).

Known Issues

Known Issues Common to Multiseat Computer Systems

The following is a list of limitations shared by many multi-station or multi-seat systems, including but not limited to Userful MultiSeat.

ACPI sometimes causes X to crash at bootup

To avoid this problem, disable ACPI by changing options in the GRUB bootloader. (The method for changing bootloader options varies depending on linux distribution and GRUB version; please see our instructions on How to Change Boot Options with the GRUB Bootloader.)

System instability with NVIDIA driver (using kernel 2.6.11-rc3 or lower)

There is a known issue regarding system instability using NVIDIA video drivers with kernel 2.6.11-rc3 or lower. If you experience random reboots or kernel panics using an NVIDIA driver, please ensure that your kernel version is 2.6.11-rc3 or higher.

Multimedia keys on keyboards are not supported

Utilities that enable multimedia keys in Linux may not work when multiple keyboards are connected to the system.

Userful MultiSeat Known Issues

Userful Control Center "Check for Updates" Page Does Not Work in v.5.0.1
Applies to: v.5.0.1

In Userful MultiSeat version 5.0.1, the "Check for Updates" page of the Userful Control Center gives an error and does not open. This issue will be fixed in an upcoming release.

Desktop Session (GNOME) Fails if Network Cable is Not Connected During System Boot
Applies to: v.5.0

If there is no network cable connected when the system is booting up, the GNOME desktop session will not start on the onboard station or on USB-connected stations. The workaround is to ensure that a network cable is plugged in during bootup. This issue will be addressed in an upcoming release.

The Manual Input Device Assignment Utility Does Not Count Unassigned Keyboards Correctly with v5.0
Applies to: v.5.0

When input device assignment is ambiguous, the Press-F-Key utility launches to allow manual assignment. With this Beta release, the available and assigned keyboards are not correctly enumerated. This is a cosmetic issue only and does not affect function.

Network Stations Not Found After Upgrading from Previous Version of Userful MultiSeat
Applies to: v.5.0

When upgrading from a previous version of Userful Multiseat (e.g. Version 4.0 or 4.1), it is necessary to fully uninstall previous versions of Userful MultiSeat before installing Userfil MultiSeat v5.0. Failure to follow this procedure will cause some network stations to be unrecognized by the Userful Control Center. In order to avoid this, uninstall the previous version of Userful MultiSeat using the Control Center before installing Userful MultiSeat 5.0.

Display Resolution Settings Will Revert to the Default Value After Rebooting
Applies to: v.5.0

In rare cases, when you set the resolution of a station (or all stations) through the Userful Control Center it will change as expected, but after a reboot the stations will revert back to the default 1024x768. The Userful Control Center will still show the user specified resolution. This is resolved by setting the resolution again.

Network Stations Status Page Freezes Due to Firefox Upgrade Issue
Applies to: v.5.0

When Firefox updates require a restart of the browser, the Userful Control Center may freeze during loading due to a Firefox message window (which opens behind the Control Center window) that requests a browser restart. This does not affect the user experience since stations are are started and users can be logged in. Shutting down and restarting the Userful Control Center will resolve this issue.

Userful Control Center Fails to Update Station User Status Correctly When a Network Station is Restarted While User is Logged In
Applies to: v.5.0

When a network station is unplugged and plugged back in, or disabled and re-enabled while a user is logged in to that station, the station will return to the log in screen. However, the Userful Control Center will still report that the user is logged into that station. This does not affect user-facing functionality, as the affected user can still log in to any station. This issue will be fixed in an upcoming release.

Keyboard and/or Mouse May be Unresponsive After Hotplugging DisplayLink-based USB MultiSeat Devices While the System is Under Heavy Load
Applies to: v.4.1 v.5.0

Frequently, when the system is experiencing a high load (for example, many users playing video simultaneously), unplugging the station USB cable then replugging it results in a log-in session with and unresponsive keyboard and mouse, making the station unusable. The system as a whole and other stations are not affected. Sometimes,turning off the device (or unplugging the USB cable) for 20-30 seconds, then turning on/replugging the station will fix the issue. More commonly, the only way to fix the unusable stations is a system reboot, Userful cautions against hot-plugging a station when the system as a whole is under load.

Some Display Resolutions Not Currently Supported with Certain Devices
Applies to: v.4.1 v.5.0

Currently, with some devices, a small number resolutions that appear in the Userful Control Center Display Management menus may not be supported. For example, with SMSC-based devices, 1366x768 or 1360x768 are not supported. This is due to graphic-chip level limitations on supported resolutions and timings. Attempting to set stations to an unsupported resolution will result in an error message and the stations will return to the default resolution (1024x768).

Kernel virtual address space exhaustion on the X86 platform with multiple NVIDIA cards
Applies to: v.4.1 v.5.0
  • For a detailed explanation of this problem and possible work-arounds, please see NVIDIA's online documentation here or here (NOTE: you must scroll down on both these pages to find the heading "Kernel virtual address space...").

On X86 systems and AMD64/EM64T systems using X86 kernels, kernel virtual address space is typically limited to 1GB or less -- and is used for direct RAM mapping, by drivers to map I/O resources and for some memory allocations.

The NVIDIA kernel module uses part of the kernel's virtual address space for each Graphical Processing Unit (GPU), which can lead to an overload of the kernel's virtual address space, particularily if more than 2 or 3 GPUs are being used. In this case, some GPUs may fail to initialize or fail memory allocations, resulting in the following error message:

allocation failed: out of vmalloc space - use vmalloc=<size> to increase size.

Possible solutions (please refer to the NVIDIA documentation above or to your system documentation for explicit instructions on using these tools):

  1. Increase the size of the kernel virtual address space (by default, the Linux kernel reserves 128MB). This is done by passing a command to the kernel via the GRUB boot menu. (The method for changing bootloader options varies depending on linux distribution and GRUB version; please see our instructions on How to Change Boot Options with the GRUB Bootloader).
    • If the above does not work, try:
  2. Disable frame buffer drivers such as vesafb.
  3. If possible, configure alternate address space layouts for your Linux kernel.
  4. If your system is equipped with an X86-64 (AMD64/EM64T) processor, it is recommended that you switch to a 64-bit Linux kernel/distribution. X86-64 kernels provide significantly larger address space than 32-bit.
Unused Video Output Heads on PCI/PCIe Graphics Cards or Integrated Graphics Cards Should be Disabled in the Userful Control Center to Avoid Going Over the Limit of Licensed Stations.
Applies to: v.4.1 v.5.0

If a graphics card on the host computer has an unused video output head (except for Radeon graphics -- please see Known Issues), that output head will still show up in the Control Center as an available station. An error message will appear stating that "The Xorg server has failed on the specified display"; this error message can safely be ignored. However, these "phantom stations" will count towards the number of seats allowed on a license -- resulting in an unusable station showing the "Too Many Stations" screen -- unless disabled in the Userful Control Center.

If "Disable All" and then "Enable All" is used, the "Too Many Stations" screen may appear on the wrong station. To remedy this situation, Disable the station formed from the unused video output head and reboot the computer.

Onboard Station Freezes When Changing Onboard Station Resolution if Using Radeon/ATI Graphics in Host Computer
Applies to: v.4.1 v.5.0

When using the Control Center to change the monitor resolution of the onboard station, a conflict with the Radeon graphics driver causes the onboard station to become unusable. If this happens, function can be restored by Resetting the System Configuration.

To avoid this problem, please do not attempt to change the resolution of the onboard station monitor if the host system has ATI/Radeon Graphics.

Unused Video Output Heads Register as X Server Failures and Count Towards Licensed Seats
Applies to: v.4.1 v.5.0

Userful MultiSeat 4.1 attempts to start a station on all available working video outputs. If no monitor is connected, the X server will fail and this will manifest as a Userful MultiSeat error message: "The Xorg server has failed on the specified display." This error message can safely be dismissed and ignored; it is a cosmetic issue that should be fixed in an upcoming release.

Only One Video Output Head of Motherboards with Dual-head Radeon Graphics Is Supported
Applies to: v.4.1 v.5.0

If the host PC system has a motherboard with integrated Radeon graphics, and also has two video output heads, only one output head will be usable with Userful MultiSeat enabled. The system will crash after reboot until a system administrator manually edits the /etc/userful/extra_devices.db to select either the VGA (D-sub) or DVI output head. To do so:

  1. Find the graphic card model used in the PC.
  2. Start the computer in single-user mode (with Userful MultiSeat disabled). Alternatively, if MultiSeat is enabled and the system has been started, wait three minutes and MultiSeat will automatically turn off, returning the system to single-user mode.
  3. Open a terminal and either log in as root or use sudo throughout this procedure.
  4. Open the /etc/userful/extra_devices.db file in a text editor.
  5. Find the # VGA devices list within that file and update it so that only one port is listed, either 'DVI' or 'D-sub' (VGA), after MainPorts.
Example: The original entry...
('video', 0x1002, 0x5b63, any, any): dict(
       Model = 'Radeon X550 (0xPCIE)',  MainPorts =  ['DVI', 'D-sub']),
Should be changed to (for DVI output):
('video', 0x1002, 0x5b63, any, any): dict(
       Model = 'Radeon X550 (0xPCIE)',  MainPorts =  ['DVI']),
Should be changed to (for VGA output):
('video', 0x1002, 0x5b63, any, any): dict(
       Model = 'Radeon X550 (0xPCIE)',  MainPorts =  ['D-sub']),
Up-Arrow Key At Session Log-in Screen Does not Work in 64-bit Ubuntu/Edubuntu
Applies to: v.4.1 v.5.0

With Userful MultiSeat v4.1 and 5.0, due to a key-mapping error, users on system using USB multiseat devices are unable to use the up-arrow key to navigate to different users at the log-in screen in 64-bit Ubuntu/Edubuntu. To workaround this issue, please use the mouse to scroll through the user list and select a user to be logged in.

Alsamixer Configuration May Be Required to get Audio Input With GWC DU2600 Multiseat Devices
Applies to: v.4.1 v.5.0

Due to an upstream Ubuntu bug, audio input through GWC DU2600 devices may not work without using Alsamixer to choose the correct sound input. For detailed instructions on how to do this, please refer to How to Set Audio Input Levels with ALSA. Further information can be found in the Alsamixer documentation.

Input Devices (Keyboards, Mice) Randomly Stop Working When Running More Than 8 USB Stations Plus Onboard Station
Applies to: v.4.0 v.4.1

This is due to a limitation on event devices in the kernel. If these problems are experienced when using an 8+1 (or larger) system, the a custom Userful-patched kernel is required. Please see Appendix C of the User Guide for more details, including download and installation instructions for the Userful-patched kernel. This does not apply to v.5.0.

Input Devices Fail to Assign with Press-F-Key Utility With 32-bit Ubuntu 10.04.03
Applies to: v.4.0 v.4.1

Rarely, when input device assignment is broken (by hotplugging the input device or USB multiseat device, by pressing Ctrl-Alt-Break, or by Resetting Configuration from the Control Center), the affected input devices will not be assignable using the Press-F-Key utility. Should this occur, the issue can usually be resolved by either unplugging the USB multiseat device (to which the affected input devices are attached) for 60 seconds, or by rebooting the system.

"Show Details" Does Not Work When Setup Wizard Stops on Unsupported Install
Applies to: v.4.0 v.4.1

During installation of Userful MultiSeat, a variety of system checks are performed; if the system checks do not pass, installation is stopped and an error dialogue appears. There should also be an opportunity for the user to get more information about the cause of the failure by clicking the "Show Details" button in the error dialogue box, however this function is not working at this time. This is a cosmetic issue and does not affect functionality.

To avoid this issue, please ensure that the operating system and system hardware meet the recommended minimums.

Devices Using MCT Chipset Must not be Plugged into an Active Userful MultiSeat System
Applies to: v.4.0 v.4.1

Due to device driver issues, please avoid plugging any multiseat device using an MCT chipset into a powered-up system that has Userful MultiSeat enabled; such devices that are hotplugged into active systems will fail to initialize properly and may cause system-wide segmentation faults.

To add one or several multiseat devices with MCT chipsets to a Userful MultiSeat system, please ensure the computer is turned off and/or has Userful MultiSeat disabled.

Onboard Audio Jack Sometimes Muted by Either AlsaMixer or PulseAudio
Applies to: v.4.0

Occasionally it seems the audio on the onboard audio is not working, when in fact it has been muted by either AlsaMixer or PulseAudio. This issue is unpredictable and difficult to reproduce. To adjust PulseAudio settings, click on the "Volume" icon in panel on the upper right-hand corner of the screen. For instructions on changing AlsaMixer settings, please see How to Set Audio Input Levels with ALSA. For further information, we recommend that if you are experiencing this problem you refer to AlsaMixer and PulseAudio documentation for how to adjust settings with those applications.

By Default, the Userful Control Center Cannot be Opened Without a Network Connection
Applies to: v.4.0

If there is no network connection, the Userful Control Center will not open unless the browser is set to "Offline Mode". There is no workaround for the Chrome browser. For Firefox, the workaround is:

  1. Use Firefox as the default web browser.
  2. If the computer is only occasionally without a network connection:
    • Attempting to open the Control Center will cause Firefox to display a page asking the user to switch to "Offline Mode". Follow the instructions on the page and the Control Center will work as usual.
  3. If the computer is regularly without a network connection, or if a more permanent fix is required:
    • Enter about:config: in the address bar of Firefox. Scroll down the page to find "toolkit.networkmanager.disable". Double-click the entry to change the value to "TRUE".
Log-in Screen Freezes and Experiences Long Delays with 32-bit Version of Userful MultiSeat4.0
Applies to: v.4.0

For 32-bit Userful MultiSeat 4.0 a custom Userful-patched version of GDM (the Gnome Display Manager) is required (This package is included in the Userful MultiSeat Linux installation DVD). This package can be downloaded from Userful's website (the checksum is here. The Userful-patched GDM file should be saved to the Desktop, and can be installed with the package manager simply by double-clicking the package icon.

Without the custom GDM package, the log-in screen experiences frequent long delays and freezing.

Chinese, Japanese and Korean Text Displayed Incorrectly
Applies to: v.4.0

CJK Characters/Fonts may display incorrectly, with black boxes instead of font characters, due to a problem with fontconfig settings. The workaround is:

  1. Open a terminal, and change to the font configuration directory:
    $ cd /etc/fonts/conf.d
  2. Enter the following:
    • For Traditional Chinese (zh_TW)
    $ sudo mv 69-language-selector-zh-tw.conf 48-language-selector-zh-tw.conf
    • For Simplified Chinese (zh_CN)
    $ sudo mv 69-language-selector-zh-cn.conf 48-language-selector-zh-cn.conf
    • For Japanese (ja_JP)
    $ sudo mv 69-language-selector-ja-jp.conf 48-language-selector-ja-jp.conf
    • For Korean (South Korea) (ko_KR)
    $ sudo mv 69-language-selector-ko-kr.conf 48-language-selector-ko-kr.conf
Note: If variant Chinese language packs such as zh_HK are installed and selected, some text strings will be displayed in Simplified Chinese only, regardless of language settings. To always display in Traditional Chinese, please remove zh_HK, and use language pack zh_TW instead.
Flash Drives Mounted in the Host Computer Cause Errors if the Volume Label Matches Any Station-Connected Drive
Applies to: v.4.0

USB flash drives have an intrinsic name called a "label". The volume labels of flash drives of the same brand name are typically identical out-of-the box (that is, Kingston-manufactured drives will be labeled "KINGSTON",. etc..) With Userful MultiSeat, any flash drives plugged directly into the host computer (system box) will result in errors accessing flash drives connected to any/all stations if the volume labels of the flash drives are the same. Please avoid using USB keys in the host computer that have the same label as keys in use on the USB-connected stations.

For instructions on how to change a USB flash drive volume label, please refer to this How To.

Atrust M200/202 & ViewSonic VMA10 USB Multiseat Devices Lose Input Assignments After Reboot
Applies to: v.4.0

With Userful MultiSeat v4.0, after every shutdown/restart, keyboard and mouse assignments are lost on all stations connected with ATrust M200/M202 or ViewSonic VMA10 multiseat. Input devices are quickly and easily reassigned with the Press-F-Key utility.

GWC DU2600 Devices Must be Re-plugged after Reboot, and Hotplugging During User Sessions Should be Avoided
Applies to: v.4.0

With Userful MultiSeat v4.0, after every shutdown/restart, stations will fail to start (resulting in a blank screen) on all GWC DU2600-connected stations. To restart the stations, the devices must be unplugged and then reconnected.

In addition, more than 50% of the time hotplugging a station with an active user session results in the user being logged off, with the potential to lose unsaved work. Userful recommends avoiding hotplugging with GWC DU2600 devices in these circumstances.

GNOME Applet Errors May Appear When Logging Into a User Session
Applies to: v.4.0 v.4.1 v.5.0

Occasionally, when a user logs into a session, an error message will appear: "Panel encountered a problem with loading OAFIID:GNOME_<applet>" and asking the user to delete or keep the affected applet. This is a known issues with the GNOME desktop environment, please see Ubuntu's bug tracking system for more information.

Userful recommends choosing to keep the affected applet as this is a cosmetic issue and does not impact functionality.

USB Video Devices Do Not Initialize on Systems with a Floppy Drive Controller
Applies to: v.4.0 v.4.1 v.5.0

If a USB video device does not initialize, USB-connected stations will not function, and the screens will either be frozen at startup or black. USB video devices may not intialize properly if:

  • the computer system has a floppy disk drive
  • the computer system BIOS has an enabled floppy drive controller (even when no floppy drive is physically present in the system)

The workaround is to disable the floppy drive controller in the BIOS. (Please refer to the documentation for your system for information on how to work with the BIOS).

Full-screen Flash Video Requires Disabling Hardware Acceleration
Applies to: v.4.0 v.4.1 v.5.0

Full-screen web-based Flash video (for example, while viewing YouTube videos) can cause Firefox to crash or freeze. Flash video can be viewed in full-screen mode, at a reduced frame rate, by disabling hardware acceleration in Flash.

Changes must be made for each user due to the way Flash settings are handled. For each user:

  1. Right-click on the Flash application.
  2. Select "Settings".
  3. Go to the "Display" tab.
  4. Un-check "Enable Hardware Acceleration".
  5. Click on the "Close" button.

These settings will be kept until changed by the user, even after rebooting the system.

Multimedia Keyboards and USB-video Devices with Network Cards Limit the Number of Stations Possible
Applies to: v.4.0 v.4.1 v.5.0

Multimedia keyboards (which have special keys to access the internet, music and other computer functions) register with computer systems as a number of separate "event devices", thus limiting the number of event devices available for multiseat stations. To achieve the maximum number of connected stations, avoid using multimedia keyboards.

Session Lock Feature Disabled to Avoid Blocking Input Device Manual Assignment Screen
Applies to: v.4.0 v.4.1 v.5.0

Session Lock is a security feature available on some Linux distributions; when the system is idle long enough for the screensaver to appear, the user's password will be required to re-open the session.

However, with Userful MultiSeat 4.0, on the rare occasion that a station loses keyboard/mouse device assignment and then the screensaver turns on, the authentication dialog box will block access to the Press-F-Key screen. Therefore, for Userful MultiSeat 4.0 the Session Lock feature has been disabled as a workaround.

Note: Users created after Userful MultiSeat is installed will not benefit from the workaround until they have logged in, logged out and logged back in once; until then the Session Lock feature will be available to those users.

Rarely, USB-connected Monitors Lose the Signal and Go Blank
Applies to: v.4.0 v.4.1 v.5.0

Certain USB multiseat devices occasionally lose their signal and go blank. This seems to be caused when fluctuations in the USB signal prompt the system to switch the device to the USB 1.1 protocol (which does not support USB-video devices due to insufficient bandwidth). It may also occur when USB multiseat devices are hotplugged rapidly. The workaround:

  1. Unplug the USB multiseat device from the computer.
  2. Wait for 45-60 seconds to allow your session to reset (please note you will lose any unsaved work)
  3. Replug the USB multiseat device into the computer and re-login.
Hewlett Packard MS6000 freezes during the boot process when some USB multiseat devices are connected to it
Applies to: v.4.0 v.4.1 v.5.0

With some HP systems (MS6000 series) using the 786G2 BIOS version 1.09 or earlier, the boot process will freeze during the Power-On Self-Test (POST) if USB multiseat devices are already connected to the system. To fix this issue, the BIOS must be upgraded to version 1.14. Please refer to Hewlett Packard's MS600 BIOS upgrade page for further details and how to upgrade the BIOS.

X Window System Fails to Start If No Monitor is Connected to Primary Station
Applies to: v.4.0 v.4.1 v.5.0

During boot-up, if no video output device is connected to the primary station, the X Window display system will not initialize properly. This is an issue with the Ubuntu/Edubuntu operating system.

To avoid this issue, always ensure that there is a monitor connected to the onboard or primary system station.

Black Box Around Cursor on Onboard/Video Card Station During Video Playback Using Xv Video Output
Applies to: v.4.0 v.4.1 v.5.0

This issue occurs on the onboard station and any PCI or PCI-e stations only. When video is being played, and the video player is using the Xv video output mode, a black square can be seen around the cursor when the cursor is moving. This is a cosmetic issue only, and seems to be restricted to systems where the onboard graphics is nVIDIA. To workaround this issue, either avoid moving the mouse cursor over a video playback window, or switch to X11 video output.

Session Log-in Screen Loses Focus When Station Enabled Through the Userful Control Center: EduBOSS OS ONLY
Applies to: v.4.0 v.4.1 v.5.0

The EduBOSS 2.0 operating system uses a deprecated version of the gnome display manager (gdm) that does not regain cursor focus properly at the log-in screen when a station is enabled through the Userful Control Center, preventing users from selected a profile to log in with.

There is a workaround for this issue; simply click on any one of the menu buttons at the bottom of the log-in screen, and then back out of the menu that pops up to return focus to the log-in prompt.

Userful MultiSeat Cannot be Installed by Double-clicking the Package in the EduBOSS Operating System
Applies to: v.4.0 v.4.1 v.5.0

EduBOSS is based on the Debian operating system which does not support double-clicking .deb packages to install them as a default behaviour. To install the Userful MultiSeat (and other) .deb package in EduBOSS, right click on the package and choose "Open with GDebi Package Installer".

Known Issues for Userful MultiSeat Linux

Spurious Error Message Appears About Install/Upgrade of "nhci-dkms" Package"
Applies to: v.5.0

During installation of certain packages (including nhci-dkms) essential for the function of USB-over-LAN stations, the system attempts to compile those packages for all available versions of the Ubuntu kernel. Due to incompatibility issues, this process fails for some older Ubuntu kernels. However, the packages do compile correctly for more recent kernel versions, including the default kernel for Userful MultiSeat Linux 5.0 (3.0.0-16). Functionality is not affected. If this error message appears, click "Close" on the dialogue box and ignore the message.

Hotplugging Too Soon After Initial User Log-in Can Prevent Subsequent Logins (For Users Created During Userful MultiSeat Linux Install)
Applies to: 2011 v.4.1 v.5.0

During the installation of Userful MultiSeat Linux, several users accounts are created. The first time one of these accounts is used to log into a session, the user is prompted to enter a new password, and the process of setting up the users home directory is completed. Hotplugging (unplugging and replugging) a station before user home directory is completed can result in a corrupted session and home directory, so that once the user logs out, that username will not be able to log into a session again.

To avoid this situation, be sure to log in and then log out each user account created during installation before hotplugging a session using those accounts.

If a user account gets corrupted in this way, it can easily be fixed by removing the /home/(username)/.userful/station folder. From either the teacher01 or the administrative account, enter the following in a terminal: sudo rm /home/student01/.userful/station/ -rf
This fix will also remove audio configuration files, so the affected user may need to reset volume levels (once, then audio levels will persist for subsequent sessions).

Disabling or Uninstalling Userful MultiSeat (from Userful MultiSeat Linux) from the Control Center May Require an Additional System Reboot
Applies to: 2011 v.4.1 v.5.0

When the Userful MultiSeat component of Userful MultiSeat Linux is disabled or uninstalled, the intended behavior is to return the system to single-user mode after a single reboot. Occasionally, disabling or uninstalling Userful MultiSeat from Userful MultiSeat Linux, from the Control Center will result in either:

  • a return to single seat mode with corrupted graphics, or
  • a failure to return to single seat mode (indicated by a black screen on the onboard station).

Should either problem occur, a manual reboot (using the power on/off or restart buttons on the host system) is required to return normal function. It may be necessary to disconnect all USB-connected stations to successfully return to single-seat mode.

X Crashes and Restarts on MCT-device Connected Stations When Streaming DVD with "watch-dvd"
Applies to: 2011 v.4.1 v.5.0

Driver segmentation faults seem to be causing X to die on stations when viewing streaming DVD on MCT devices using the Userful MultiSeat Linux "watch-dvd" function. There is no workaround at this time.

User Cannot Fully Change Session Language From Log-in When Userful MultiSeat Linux is Installed in a Language Other Than English
Applies to: 2011 v.4.0

From the Ubuntu/Edubuntu login screen, users are supposed to be able to choose a session language; however when Userful MultiSeat Linux is installed in a language other than English, and a user chooses a session language other than the system language, user interface translations are not working. Only the date will appear in the user's chosen session language. All else will be in the system language.

This bug is related to a bug in Ubuntu; see Ubuntu's bug tracking system for more details.

The workaround is for an administrator to change the system language using the Language Selector, accessed through Administration > Language Support. Please see How to Change System Language for more information.

Contact Userful

Website: (company home page: )
Phone: 403-289-2177 extension 2
Toll-Free: 1-866-873-9119

(Within North America only -- International Clients please use the direct line, 1-403-289-2177).

(Note: Office hours for telephone support: Monday to Friday, 8:30am - 5:30pm MT (UTC-6 or UTC-7))