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I am using an Ubuntu Server EBS-based AMI on Amazon EC2. I have installed the desktop packages and ssh -X to my machine using the default ubuntu account but when I enter the command:


I get the following output:

X: user not authorized to run the X server, aborting.

What do I need to do to get a remote X session running from here?

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Do you actually want a full desktop, or is running individual tools adequate? What client OS are you connecting from. – Zoredache Nov 6 '10 at 3:37
I do want a full desktop. I am connecting from OS X and have successfully run remote desktop sessions from another Ubuntu machine on my LAN. – ProbablePattern Nov 6 '10 at 12:36
Beware programmers carrying screwdrivers... – gWaldo Nov 7 '10 at 1:43
@gWaldo There are some programs that can't be run without a screen. (At least as far as I can tell, this is the easiest or only solution java headless-exceptions.) – isomorphismes Dec 17 '12 at 2:23

startx is used when you want to run a full X server, which is almost never what you want to do on a remote system. Instead, just run the app directly and ssh will forward the X messages to your local system.

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Even when I use ssh -X -C -i key.pem ubuntu@mymachine to login, I can't get an X session. – ProbablePattern Nov 6 '10 at 3:17
Have you double checked. Maybe X11 forwarding is disabled in your sshd_config. – Zoredache Nov 6 '10 at 3:34
X11 forwarding is set to yes in sshd_config – ProbablePattern Nov 6 '10 at 12:48

Are you sure that you do, indeed have X installed? One clue would be to see if you have an /etc/X11/xorg.conf (especially if it's not just a blank file)

Also, do you have any GUI apps installed?

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sudo xinit

Do you have gnome-desktop-environment installed?

BTW, you can look through programs to install with apt-cache search gnome-desktop. Might be helpful in whatever you're trying to do.

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