Fowarding X output from a server to a workstation

Question

I'm trying to set up the backup service for a server at work. Specifically, we are using the online backup service SpiderOak. It seems like a fantastic program except for one fact: it uses a graphical interface to do all account setup and management. This isn't a problem in the long run since it runs in the background to do all backups, but right now I'm struggling to get it configured.

My server, of course, doesn't have X or any GUI installed. It seems like a no-brainer to use SSH (with the -X flag for X forwarding) from a GUI-enabled Linux workstation to set it up (in fact this is recommended in the official documentation for the program). The problem here is, it doesn't work.

This is my output:

dan@cobalt:~$ SpiderOak
Fontconfig error: Cannot load default config file
SpiderOak: cannot connect to X server

So, how do I forward X output from my GUIless server to my workstation?

Answer 1

By default Ubuntu Server (as of 9.04) does not have xauth installed. You will need to install via apt-get as root or via sudo.

[root@myserver]# apt-get install xauth

In General it's a good idea to verify your SSH settings. On your server check to make sure /etc/sshd_config contains:

X11Forwarding yes

On your client ensure /etc/ssh_config contains:

ForwardX11 yes

To verify if X is forwarding try:

[root@myserver]# xclock

If it works you know that your X is forwarded.

Answer 2

You need to install a few minimal X11 packages on your server. Not the whole thing, but stuff like xauth and fonts. You didn't mention your distro, but on RedHat/CentOS that would be like xorg-x11-xauth and xorg-x11-fonts-base. Often times, installing 'xterm' will pull in all the necessary dependencies for you. Sorry I don't know the whole list of required packages/files offhand.

Once that's done, on the server, double-check SSH X11 forwarding is working by typing:

echo $DISPLAY

You should see something like "localhost:10.0" if it's working, or a blank line if it's not.