Display Failures when using VNC

Version 5

    In various of cases, when trying to launch applications such as wireshark, virt-manager or similar from the VNC, you get an error similar to this:

    # virt-manager

     

    ** (virt-manager:5488): WARNING **: Could not open X display

    Gtk couldn't be initialized

     

    To solve it:

    1. Make sure you are connected to the server with ssh and "-X" option

     

    For example:

     

    ssh root@my-server -X

     

    2. In other cases, it means that the DISPLAY parameter is not set properly to be the VNC window.

    # echo $DISPLAY

    <empty>

     

    To set the DISPLAY parameter run (for example):

    # export DISPLAY=i-vnc01:2

     

    Now you should be good to launch your application.