Frequently asked questions (FAQ)

OS support

  • jFed experimenter GUI now requires java 8 on all platforms. Only the oracle implementation is tested.
  • Older versions will run on java 7, but only with at least Oracle Java 7 install (Update 55 or higher). On Linux, your mileage may vary with these older version, they tend to freeze on some Ubuntus e.g.
  • jFed currently does not support Open JDK. It should in theory work if you correctly install OpenJXF, but this is untested.

Install problems

Be sure to run a recent Java 8, verify with http://java.com/verify and/or java -version. If you have 2 java installations on your PC, you may revert to the command line start up of the Java 8 one, by downloading from http://jfed.iminds.be/releases/ the latest release and take the Experimenter GUI - Download jar.

Run this with something comparable to:

C:\Users\bvermeul\Downloads>"c:\Program Files (x86)\Java\jdk1.8.0_X\bin\java.exe" -jar "jFed-experimenter-GUI.jar"

This will help also to show you console output to detect what is wrong.

SSH login problems

  • If you do not get connection to the node, try to enable the proxy support in the preferences
  • If it still keeps saying Server refuses key, check in Putty on Windows that there is no fixed private key in the default settings of Putty (Connection - SSH - Auth - Private key file for authentication)
  • If you used “Edit SSH Keys” but can’t login afterwards, one possible reason is that “Edit SSH Keys” needs to assign specific uid’s for the added users. So if any boot script or manual editing on the node has added a user without specifying a uid, the needed uid will not be available and sharing SSH keys won’t work.

Linux SSH terminal

Not all linux systems have the same SSH terminal, but if the default one does not work (when you right click a node when it is green, no SSH terminal opens), you can change terminals in jFed preferences as shown below.

Terminals to try:

konsole -e %
gnome-terminal -e '%'      (quotes should be right !)
xterm -e %
x-terminal-emulator -e %
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