Department of Electrical Engineering and Computer Science



RealVNC Access to EECS Linux Systems

Some EECS Linux systems allow remote access via the RealVNC® VNC Viewer, providing a secure (encrypted) desktop connection. This is often much faster than using X11-forwarding via SSH. Please not that, unlike with Microsoft Windows Remote Desktop connections, disconnecting the client will not leave your session open on the system but will instead end it. Please log out properly before disconnecting from the remote system.

Quick Start Guide

Step-By-Step

  1. Download and install the free RealVNC® Viewer, available for Windows, MacOS, Linux, Solaris, AIX, and HP-UX.

    The Apple App Store and Google Play both have mobile versions of the RealVNC® Viewer available, however they are not free:

    Available_on_the_App_Store_Badge_US-UK_135x40_0824.png  Get it on Google Play

    You cannot use other VNC clients as they do not provide encryption of your connection.

  2. Connect to screen number 99 on a RealVNC® enabled EECS Linux system by choosing system_name.eecs.utk.edu:99 as the VNC Server. For example, to connect to vnc11.eecs.utk.edu, enter the following:

     realvnc_connect.png
  3. The first time you log into a specific system, you will be asked to confirm acceptance of the server signature, much like you would with SSH:

    realvnc_sig.png

    If you have any doubts about the authenticity of the server's signature, you can verify it from a command line. See the FAQ below.
  4. Enter your EECS username and password:

     realvnc_password.png
  5. You will be logged into a standard desktop session on the selected system. In most cases, this will be a version of the Gnome environment:

     realvnc_desktop.png

  6. When you are finished with your work, log out as you would on any standard EECS Linux system:

     realvnc_logout.png

FAQs

How do I change my VNC screen resolution?

By default, the VNC system will create a window with a resolution of 1024x768. You can change this, both temporarily or for every login. To change resolutions on the fly, open a terminal window and run the following command to see the available resolutions:

jruser@vnc11:~> xrandr
SZ: Pixels Physical Refresh
*0 1024 x 768 ( 260mm x 195mm ) *0
1 1440 x 900 ( 366mm x 229mm ) 0
2 1600 x 1200 ( 406mm x 305mm ) 0
Current rotation - normal
Current reflection - none
Rotations possible - normal
Reflections possible - none

You can now choose a new resolution by using the xrandr -s command, e.g. to switch to 1440x900 in the above example, run xarndr -s 1.

To change your default resolution for all your login sessions, regardless of VNC server, create a file called ~/.vnc/config. Add a -geometry option to the file, e.g.:

jruser@vnc11:~/.vnc> cat config
-geometry 1440x900

The next time you log into a VNC system, your window will have the resolution you specified. Note: This has to be one of the available resolutions as shown by the xrandr command explained above.

How do I print to my local printer?

Just like on regular EECS Linux systems, you can print to departmental printers while connected via VNC. In addition, the VNC client will automatically add the default printer on your client computer to the list of available printers. This allows you to print a remote document directly through the VNC Viewer to your own printer. If your default printer is called "My Printer", VNC will create a printer list entry called My_Printer_via_VNC_from_IPNAME where IPNAME is the network name of your client system. You can still pick any of the departmental printers from the printer list if you prefer.

Can I transfer files between my client and the VNC server?

The RealVNC® Viewer has a secure file transfer feature built-in, similar to a simple FTP or SFTP client. To send files from your local computer to the VNC server, click on the VNC toolbar (by default, this is at the top of your VNC window and will pop-out when you hover over it) and select the File Transfer icon:

 realvnc_filetransfer1.png

To transfer files from the remote VNC server to your local computer, open the VNC Server application in the remote system's status bar, then click "More" and select File Transfer:

realvnc_filetransfer2.png

Simply follow the instructions to transfer files between the computers. 

Can I get a persistent VNC connection that survives disconnects?

Yes - but with some important caveats. The access method described above makes it easy to connect to a VNC system, do your work, and then disconnect without leaving a lot of processes running. It is, however, possible to create a persistent connection that will survive disconnecting. You can then later reconnect to the same session, finish your work, log out, and remove your session. 

NOTE: The EECS IT Staff reserves the right to kill any sessions that are using an undue amount of system resources (CPU time, RAM, etc.) and make it impossible for other users to share the system. Please remember that these computers are shared resources.

To get a persistent VNC connection, first log into the system of your choice (it has to be a system supporting RealVNC®) via SSH - see the Remote Access knowledgebase article for more information on SSH connections.

Once you are logged in, run the vncserver-virtual command manually.

jruser@vnc11:~> vncserver-virtual
VNC(R) Server 5.0.3 (r97046)
Built on Oct 2 2012 16:42:29
Copyright (C) 2002-2012 RealVNC Ltd.
VNC is a registered trademark of RealVNC Ltd. in the U.S. and in other
countries.
Protected by UK patent 2481870.
See http://www.realvnc.com for information on VNC.
For third party acknowledgements see:
http://www.realvnc.com/products/vnc/documentation/5.0/acknowledgements.txt

Running applications in /home/jruser/.vnc/xstartup
VNC Server signature: 54-40-b9-e9-77-5c-99-f3
Log file is /home/jruser/.vnc/vnc11:1.log
New desktop is vnc11:1 (160.36.56.159:1)

Make a note of the desktop number. In the above example, it is desktop 1 (New desktop is vnc11:1 (160.36.56.159:1)). You can now log off from your SSH session if you so choose. Connect to desktop 1 instead of desktop 99 (in our example vnc11.eecs.utk.edu:1) using the RealVNC® Viewer. 

To end the persistent VNC session, first log out of your desktop environment as usual. Next, log in using SSH and run vncserver-virtual -kill :desktop_number - in our example this would be: vncserver-virtual -kill :1. If you neglect to kill your VNC server, it will continue to respond to login requests but will not have an associated desktop environment and thus become unusable.

VNC asked me to accept a server signature - how can I know it's correct?

Coming soon.

Where can I get more information on RealVNC?

Each RealVNC® enabled EECS system has manual pages for the various components of VNC (e.g. vncserver-virtual and Xvnc). Simply use the "man" command to get more information on command-line options, etc. Most manual pages are also available at the RealVNC® command line reference website.  Additionally, user guides can be found at the RealVNC® documentation site.


 

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