Turn off display on Linux

The command is:

xset -display :0 dpms force off[/code]

I had to send the command twice in succession to turn the monitor off

You are reading this post on Joel G Mathew’s tech blog. Joel's personal blog is the Eyrie, hosted here.

Nvidia driver issue on Kubuntu 12.05

I’d upgraded Kubuntu 11.10 to 12.05, then accidentally run the Nvidia installer, overwriting my kernel module with an older module. At boot, I got the following error message:

NVRM: API mismatch-client has version 295.20 while module has version 295.40
No screens found, X cannot start. Some configurations were found but were unusable.

I could not reinstaller the NVidia installer again.

Found out the kernel module location:

[[email protected] ~]$ modprobe -l |grep nvidiakernel/drivers/video/nvidia/nvidiafb.ko
[[email protected] ~]$ ls -l /lib/modules/
total 12
drwxr-xr-x 3 root root 4096 May 8 06:47 3.0.0-12-generic
drwxr-xr-x 5 root root 4096 May 8 23:05 3.0.0-19-generic
drwxr-xr-x 5 root root 4096 May 8 23:06 3.2.0-24-generic
[[email protected] ~]$ sudo mv /lib/modules/3.2.0-24-generic/kernel/drivers/video/nvidia nvidia_old/
[[email protected] ~]$ sudo mv /lib/modules/3.2.0-24-generic/kernel/drivers/vi nvidia_old/video/ virtio/
[[email protected] ~]$ sudo mv /lib/modules/3.2.0-24-generic/kernel/drivers/video/nvidia.ko nvidia_old/
Load muon software installer and uninstall the Nvidia package.

Running the command:

dkpg-reconfigure xserver-xorg[/code]
will fix your
xorg.conf if you mess it up, but it won't fix the API mismatch (via http://ubuntuforums.org/showthread.php?t=650161)

Update: The above did not work for me this time. After purging the module, and downloading and reinstalling the Nvidia official installation, the system gave me the ubiquitous green and black screen.

What I did to solve my issue:
Boot into recovery root shell.

dpkg --purge nvidia-*[/code]
It will give a warning that nvidia-common cannot be uninstalled due to dependency issues, but that's fine.

Boot into recovery, then into graphical screen.
Open muon software installer and install the current driver.
If you're using apt, it will be:

apt-get install nvidia-current[/code]

reboot and you're good to go!


Update on the issue:

The issue recurred a few weeks later. I dont remember modifying anything in Ubuntu at the time, but somehow I got the same message that the kernel module conflicted with an API. I tried:

dpkg --purge nvidia*

But it said nvidia-common could not be removed as it was a dependency for KDE. I forced a purge with:

dpkg --purge --force-all nvidia*

Rebooting would not have started nvidia, so I rebooted to recovery and resumed.

You are reading this post on Joel G Mathew’s tech blog. Joel's personal blog is the Eyrie, hosted here.

Install NVIDIA drivers on Ubuntu 11.10

I had a rather peculiar issue with my Geforce card and Ubuntu. I’d get a strange looking graphic on trying to boot X normally. It would boot fine in recovery mode, and if I chose to continue loading Linux in recovery, X would start just fine.

Following are the steps to install:

sudo apt-get install build-essential linux-headers-`uname -r`
sudo /etc/init.d/kdm stop
cd /path/to/installer
sudo chmod +x NVIDIA*
sudo sh NVIDIA*
sudo /etc/init.d/kdm start
kdesu nvidia-settings[/code]

You are reading this post on Joel G Mathew’s tech blog. Joel's personal blog is the Eyrie, hosted here.

Installing Nvidia Graphics driver under Kubuntu

I’ve had a weird issue. My Kubuntu install would never start Xorg. I could boot to recovery, then make it “resume normal boot”. But it would never boot on its own. I pinned the issue on graphics drivers.



My Graphics Processor is Nvidia GeForce 8400 GS



Driver download page

Latest Ubuntu 32 bit display driver (as of Jan 23, 2012)



This downloads a 32 MB executable file NVIDIA-Linux-x86-290.10.run

Boot to Ubuntu recovery, navigate to the folder containing NVIDIA-Linux-x86-290.10.run



First install binaries required to rebuild kernel:



sudo apt-get install build-essential[/code]



Then install the driver:

sh NVIDIA-Linux-x86-290.10.run[/code]


Now you can start X with:

sudo /etc/init.d/kdm start[/code]


Add Nvidia module to start with

kdesudo kate /etc/modules[/code]

Add a line "nvidia" on a new line
Once Nvidia drivers are installed, you can configure them with:

kdesudo nvidia-settings[/code]

For more instructions, refer the following:


You are reading this post on Joel G Mathew’s tech blog. Joel's personal blog is the Eyrie, hosted here.