Recently after performing a Kernel update my CentOS machine refused to boot. Stopping while “starting jexec services”.
Firstly to get started on the fix you need to be able to boot, so if you restart the machine and at the Grub loader, press ‘e’ to edit your default linux boot option. You then move down to the kernel line and again press ‘e’ to edit. After it says quiet add a 3, this tells the kernel to boot into init 3, no graphical interface.
Once this is done, press enter to save, then press ‘b’ to boot. The machine will boot but to the commandline. From here log in, and then move your XOrg config file out of it’s normal directory to for example /home/yourusername/.
you can then restart your machine with
shutdown -r “now”
the machine will now boot but without hardware acceleration for the graphics.
Once this is done you can then download the latest version of your display driver. For me on a 64 bit machine running an NVidia 8600 GT that was, http://www.nvidia.com/object/linux-display-amd64-304.88-driver.html
Then change the permissions of the download .run file with chmod u+x so you can execute it from the commandline.
As root, open a terminal and run init 3 to drop to the commandline. Then move to the location of the downloaded driver and run it with ./NVIDIAXXXX.run.
Complete all the questions in the set up and I personally chose not to install the 32bit OpenGL compatibility.
Once this is all complete you can restart again and you will notice your res is clearer but if you have multiple monitors it will only be running on one.
Once logged in you can open the NVidia X Server settings GUI and you will see your multiple displays, for me I had to swap them around and explicitly set one to have a position of “Left of” the other screen.
Once done, save the conf, if it wont let you get it to show details, copy the contents then as root save that into your /etc/X11/xorg.conf file then you should be done.