"Unable to open display " "" error on VNC Server

Question

I'm trying to run a GUI for my CentOS 6 server. I've installed VNC, and I have followed this guide through to the end - http://wiki.centos.org/HowTos/VNC-Server

Once the VNC server is started, I try to access it through the command:

vncviewer -via username@xxx.xxx.xxx.xx localhost:1

... just like the guide said. Once this runs, it asks for my password for the account, and then displays this error:

vncviewer: unable to open display ""

I've installed GNOME display as stated in the guide, by using the command:

yum groupinstall Desktop

Any ideas?

Edit: I'm on the CentOS server in question, which looks like terminal at the moment.

I'm trying to get a GUI display running on it, I've entered the command after starting the server vncviewer -via user@ip localhost:1 but it resulted with the same error:

vncviewer: unable to open display ""

In my /etc/sysconfig/vncservers file, I have:

VNCSERVERS="1:user" 
VNCSERVERARGS[1]="-geometry 800x600 -localhost"

Output of netstat -plunt | grep 5901 :

tcp        0      0 127.0.0.1:5901       0.0.0.0:*    LISTEN      29577/Xvnc

Edit #2: After installing the new packages and running 'startx', it ran for a while. I then recieved a few errors:

Fatal server error:
(EE) no screens found(EE)
Server terminated with error (1). Closing log file.

It looks like it created a log file of the error. Forgot to mention: After this process errored, Putty encountered a fatal error, causing a connection abort.

Edit #3: Running the command 'init 5' seems to break my server. Had a 'connection error' after running it. Cannot connect back, going to have to get the admins to restart it from their side.

Answer 1

This is the correct way to install vnc server:

Install the following packages:

yum install pixman pixman-devel libXfont tigervnc-server.x86_64 -y

Edit the file /etc/sysconfig/vncservers and add the following lines:

VNCSERVERS="6:<LOGIN_NAME>"
VNCSERVERARGS[6]="-geometry 1152x864"

In the first line, "6:" means that the vnc server daemon will listen on port 590[6] and will log into the specified user's desktop.

Example:

Having "5:itai" there will make the server listen on port 590[5] and connect to itai's desktop.

Then run in order to make sure vncserver starts with boot:

chkconfig vncserver on

Then, set a password for that user, run it from the user's shell (the user you specified in /etc/sysconfig/vncservers):

/usr/bin/vncpasswd

And restart the daemon:

/etc/init.d/vncserver start

Edit #1:

It seems like you installed only the Desktop packages, as far as I know you will need these as well:

yum -y groupinstall "Desktop" "Desktop Platform" "X Window System" "Fonts"

Then run:

init 5
startx

Answer 2

try to add -listen tcp in VNCSERVERARGS:

VNCSERVERARGS[2]="-geometry 800x600 -listen tcp"