View Full Version : [ubuntu] x11vnc on 10.04 "password check failed"

September 15th, 2011, 08:56 PM
I did this from here:

Setting up X11VNC server under Ubuntu 10.04

This is a simple guide on setting up X11VNC on a system running Ubuntu 10.04 in a headless configuration. Good Luck, and YMMV.

1. Terminal > sudo apt-get install x11vnc
OR compile x11vnc from source: http://www.karlrunge.com/x11vnc/

2. Terminal > sudo nano /etc/gdm/Init/Default

2.1. Add on the second last line:
/usr/bin/x11vnc -xkb -rfbauth /etc/x11vnc/passwd -o /etc/x11vnc/log -bg -forever
OR if you compiled from source, add the following line:
/usr/local/bin/x11vnc -xkb -rfbauth /etc/x11vnc/passwd -o /etc/x11vnc/log -bg -forever

2.2. Terminal > sudo mkdir /etc/x11vnc

2.3. Terminal > sudo touch /etc/x11vnc/log

2.4. Terminal > sudo x11vnc -storepasswd /etc/x11vnc/passwd
Follow the commands to store your password. Alternatively, if you do not wish to use a password, do not run this line and remove the -rfbauth /etc/x11vnc/passwd section from /etc/gdm/Init/Default

3. Terminal > sudo restart gdm

You now have a fully configured, headless VNC setup. Congratulations! Please note that your VNC session will end whenever you log out of GDM, this is a problem with GDM killing the X11 session. X11VNC will start up again with the new X11 session at the login screen, so nothing to worry about, just reconnect!

Then I did this from here:

(This HOWTO will cover different aspects you might not need all of this, but if you need a) a custom resolution b) setup headless access c) access to the console (display :0)remotely part of this may be useful to you.)

So this was going to be a question but it turned into a HOWTO after spending hours on this.

PROBLEM #1: I needed remote access to the console (display :0) of a server from a laptop because I needed to access the audio hardware (though I'm sure there are different reasons one needs access to :0) so nx, tightvnc, xvnc were all out.
PROBLEM #2: The server had no monitor attached
PROBLEM #3: I was connecting with a laptop that had a resolution of 1280x800 but of course windows (and other OSes) have a task bar, so the actually workable area is less than that. I needed a resolution of 1224x685 (not your typical resolution).
PROBLEM #4: need the vnc server to start at boot to allow login from the server (no monitor).

1) Install x11vnc (this seems to be the only vnc server I found that allows console access, nomachine 4 (coming soon) and nomachine 3 have some form of 'physical screen' access, but I had a hard time with managing the audio hardware with that so I needed to use vnc.

sudo apt-get install x11vnc

2) To make x11vnc start at boot, create a password (instructions here: http://www.karlrunge.com/x11vnc/faq.html#faq-passwd) with the xserver place the following at the bottom of /etc/gdm/Init/Default

/usr/bin/x11vnc -forever -rfbport 5900 -rfbauth /etc/x11vnc.pass -auth guess -display :0 -bg -shared -noxdamage -xrandr

This will start your vnc server when your xserver starts.

3) Modify grub so that your kernel doesn't start a modeline module. Edit /etc/defaults/grub and make sure your GRUB_CMDLINE_LINUX_DEFAULT variable includes a 'nomodeset' flag:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash nomodeset"

(I'm not certain if that step is necessary, but I think so.)

4) Install the 'dummy' xorg driver. This tells the xserver that there is no monitor:

sudo apt-get install xserver-xorg-video-dummy

5) Modify your /etc/X11/xorg.conf file. The xserver tries to do everything it can to get settings form the monitor. We need to disable all this and the 'dummy' driver might not be enough, hence the NoDDC AND IgnoreEDID. Here is my xorg.conf:

Section "Monitor"
Identifier "Monitor0"
HorizSync 28.0-80.0
VertRefresh 48.0-75.0
#Modeline "1280x800" 83.46 1280 1344 1480 1680 800 801 804 828 -HSync +Vsync
# 1224x685 @ 60.00 Hz (GTF) hsync: 42.54 kHz; pclk: 67.72 MHz
Modeline "1224x685" 67.72 1224 1280 1408 1592 685 686 689 709 -HSync +Vsync

Section "Device"
Identifier "Card0"
Option "NoDDC" "true"
Option "IgnoreEDID" "true"
Driver "dummy"

Section "Screen"
DefaultDepth 24
Identifier "Screen0"
Device "Card0"
Monitor "Monitor0"
SubSection "Display"
Depth 24
# Virtual 1280 800
Modes "1224x685"

6) Add a custom resolution. You'll notice my custom resolution above (the two calls to "1224x685"). I used this calculator to generate the modeline (but there are many cli and online calculators):


If you need something else, use that calculator and replace the relevant parts.

7) Restart the computer and log into your sever with a vncclinet and enjoy your custom-resolution, headless, vnc.

Note that vnc is not encrypted after login so if you need this procedure of important information you should run this though an SSH tunnel (see other howtos). I may have forgot something here, so if you need help, I'm subscribed to this thread and I would be happy to help, or you can find me as 'aaas' on IRC.


When I try to connect now I get a "Status: Security type requested" and then in the password prompt I input my pw as set (and reset/rebooted) by "sudo x11vnc -storepasswd /etc/x11vnc/passwd"

Finally, that results in "password check failed"

Any advice?

September 15th, 2011, 10:08 PM
Solved: Step 2 in second section should be /pass not .pass