X server doesn't work on Ubuntu 14.04. What may be happening?

Question

This how I used to setup my X Server on Ubuntu 13.

apt-get update
apt-get upgrade

# nvidia
apt-get -y install nvidia-current
apt-get -y install nvidia-current-updates

# x server
apt-get -y install xserver-xorg
apt-get -y install x11-xserver-utils

export DISPLAY=localhost:0.0

X :0 &
xhost +

On Ubuntu 14, I am getting the following error when I do X :0:

[  3491.124] (II) Module wfb: vendor="X.Org Foundation"
[  3491.124]    compiled for 1.15.1, module version = 1.0.0
[  3491.124]    ABI class: X.Org ANSI C Emulation, version 0.4
[  3491.124] (II) Loading sub module "ramdac"
[  3491.124] (II) LoadModule: "ramdac"
[  3491.124] (II) Module "ramdac" already built-in
[  3491.125] (**) NVIDIA(0): Depth 24, (--) framebuffer bpp 32
[  3491.125] (==) NVIDIA(0): RGB weight 888
[  3491.125] (==) NVIDIA(0): Default visual is TrueColor
[  3491.125] (==) NVIDIA(0): Using gamma correction (1.0, 1.0, 1.0)
[  3491.125] (**) NVIDIA(0): Enabling 2D acceleration
[  3491.569] (II) NVIDIA(0): NVIDIA GPU GeForce GTX 650 Ti (GK106) at PCI:1:0:0 (GPU-0)
[  3491.569] (--) NVIDIA(0): Memory: 2097152 kBytes
[  3491.569] (--) NVIDIA(0): VideoBIOS: 80.06.3c.00.11
[  3491.569] (II) NVIDIA(0): Detected PCI Express Link width: 16X
[  3491.569] (--) NVIDIA(0): Interlaced video modes are supported on this GPU
[  3491.572] (--) NVIDIA(0): Valid display device(s) on GeForce GTX 650 Ti at PCI:1:0:0
[  3491.572] (--) NVIDIA(0):     CRT-0
[  3491.572] (--) NVIDIA(0):     DFP-0
[  3491.572] (--) NVIDIA(0):     DFP-1
[  3491.572] (--) NVIDIA(0): CRT-0: 480.0 MHz maximum pixel clock
[  3491.572] (--) NVIDIA(0): DFP-0: 165.0 MHz maximum pixel clock
[  3491.573] (--) NVIDIA(0): DFP-0: Internal Single Link TMDS
[  3491.573] (--) NVIDIA(0): DFP-1: 330.0 MHz maximum pixel clock
[  3491.573] (--) NVIDIA(0): DFP-1: Internal Single Link TMDS
[  3491.573] (EE) NVIDIA(0): Failed to assign any connected display devices to X screen 0
[  3491.598] (EE) NVIDIA(0): Failing initialization of X screen 0
[  3491.782] (II) UnloadModule: "nvidia"
[  3491.782] (II) UnloadSubModule: "wfb"
[  3491.782] (II) UnloadSubModule: "fb"
[  3491.782] (EE) Screen(s) found, but none have a usable configuration.
[  3491.782] (EE) 
Fatal server error:
[  3491.782] (EE) no screens found(EE) 

What else can be done?

Solution

I found the final solution here: http://www.nvidia.com.br/download/driverResults.aspx/69539

There's an item it says:

• Add a new option, AllowEmptyInitialConfiguration, which allows the X server to start even if no connected display devices are detected at startup. This option can be enabled by running "sudo nvidia-xconfig --allow-empty-initial-configuration"

So I did:

sudo nvidia-xconfig --allow-empty-initial-configuration

And it worked.

It happened because this is a server and in fact it doesn't have any display device connected.

Also, before it I followed the advice of bodhi.zazen. I blocked the nouveau drivers [and other stuff I think]

I added to /etc/modprobe.d/blacklist.conf

blacklist vga16fb
blacklist nouveau
blacklist rivafb
blacklist nvidiafb
blacklist rivatv

Then I rebooted, reinstalled the NVDIA drivers... and rebooted again!

Comments

[Admin]

It looks like a problem with NVIDIA this discussion may help with your problem also google the two errors you have. "NVIDIA(0): Failed to assign any connected display devices to X screen 0" and "Screen(s) found, but none have a usable configuration" both of kind of lean towards drivers for NVIDIA graphics and ubuntu.

[Panther]

You should try rebooting to see if that resolves the problem after installing the nvidia driver.

[Wagner Patriota]

I always reboot after any changes... I also have the DISPLAY=localhost:0.0 in /etc/environment

[Panther]

Not sure why you feel you need to set the DISPLAY variable, X will start without setting this variable. I am not sure if that is even a problem or why you are setting xhost ;)

[Wagner Patriota]

actualy nevermind about the DISPLAY variable... this is for sure not the issue. The thing is that I can't turn X Server on...

[Panther]

OK, check the logs to see if there is a more specific error. Assuming the closed source driver is not working and the logs do not geve more information, your options are going to be limited to : 1. File a bug with Nvidia ; and / or use the open source driver (nouveau). The open source driver is built into the kernel (well module) so remove the nvidia driver and try again.

[Panther]

That is an old link on the forums and does not really answer the question. "... Screen not found" is a very non-specific error message.

[web.learner]

What graphics card do you have? Is it dual Intel/Nvidia? Could you upload the full Xorg.0.log (found in /var/log) to paste.ubuntu.com and link it here?

[Wagner Patriota]

I don't think it's dual. When I do lspci, I only get 1 VGA [VGA compatible controller: NVIDIA Corporation GK106 [GeForce GTX 650 Ti] (rev a1)]

[Wagner Patriota]

if you saw the other log, ignore it. I posted the wrong thing... now, my scenario is this: pastebin.com/Ex4K824g bacause I tried to install the driver from NVIDIA and from apt-get and removed many times... It seems to be conflicting now...

[Wagner Patriota]

I did what you said and something else... I will post as aswer for somebody else... thank you very much!

[Wagner Patriota]

Thank you @Seth and bodhi.zazen! It's working now! It happened because it's a server and doesn't have any monitor connected.

[ComputerScientist]

just to be clear, does this mean that if you log into your remote machine, and type in nvidia-smi, you will see /usr/lib/xorg/Xorg as one of the process names? I'm in the same situation as you with Ubuntu + no display device (but with NVIDIA GPUs).