What is the most simple example to check if X11 forwarding is working?
Instead of the ssh command you issued, try:
$ ssh -v -Y user@cluster
Add another argument -v
enable the debugging mode for ssh
command. Search for a line containing Requesting X11 forwarding
, like in:
$ ssh -v -Y user@cluster
[...]
debug1: Requesting X11 forwarding with authentication spoofing.
[...]
After logging in, you can try the following commands for opening a X window: xterm
, xclock
, xcalc
, xedit
, etc These were already mentioned in comments.
You asked for a dialog box with a custom text, so you should try xmessage
:
$ xmessage -center hello!