I have set up X desktop and want to connect to the X server through ssh. As you know ssh provides X forwarding which is a very useful feature and used a lot of system administrators.
Try To Connect Ssh X Forwarding
We will try to connect the X service of remote ssh server by providing -X
parameter.
$ ssh -X ubu1
OR
$ nautilus

We get an error like “Unable to init server: Could not connect: Connection refused” or “/usr/bin/xauth: /home/ismail/.Xauthority not writable, changes will be ignored”
Change Ownership Of Xauthority
We will change Xauthority file ownership because it will be used by the current user to read and write.
$ sudo chown ismail:ismail .Xauthority

Check Disk If It Is Full
One of the root cause of a lot of problems is fulling disk. It is a hidden problem and generally does not show himself. We should all ways count this option for troubleshooting.
$ df -lh

As we can see in the third line of output our root path have enough free space to run X
Check Ssh Server X Forwarding Setting
The ssh server configuration has a line X11Forwarding which enables or disable X11 forwarding. It may be disabled because of security reasons.
$ cat /etc/ssh/sshd_config | grep X11Forwarding

Check Ssh Client ForwardX11 Setting
The client-side of the ssh configuration also includes X11 forwarding. It shouldn’t be disabled or explicitly enabled like below.
$ cat /etc/ssh/ssh_config | grep ForwardX11

We should uncomment line ForwardX11 no and change to yes.