[CentOS] X Servers xorg.conf file changing.

Wed Apr 21 16:36:29 UTC 2010
Ned Slider <ned at unixmail.co.uk>

Don Krause wrote:
> Twice now over the past year, I've had something edit the /etc/X11/xorg.conf file without user intervention.
> 
> The machine in question is a 3 headed X-Terminal that displays the accelerator control system application for a medical proton accelerator, and operated by staff who do NOT have root or root like access (sudo) on the X-Term, as once it's configured, it should never need changing. It lives on a private network (Network? Actually a crossover cable to the Sun box in a protected environment) with no reachable route even from within the organization.
> 
> Out of the blue, on 2 occasions now, an entry for 1 of the video cards (out of 3) has changed it's driver entry from "nvidia" to "nv". This, of course, prevents X from starting.
> 
> This morning, while of the phone with the field service tech, I corrected the entry, set the xorg.conf file to 444, and when they rebooted the X-Term, it again changed the entry from "nvidia" to "nv".
> 
> Again, I corrected the xorg.conf file, reset it to 444, and rebooted the X-Term again, and it started fine, no changes.
> 
> This box does get rebooted quite frequently, yet the unexpected change has only happened 3 time total, once 6 months and probably 30+ reboots ago, and again twice this morning on back to back reboots. (Yet the third and forth reboots did NOT change the file)
> 
> I've never seen this happen before, and am at a bit of a loss wondering where to look.
> 
> CentOS 5.3, 2.6.18-128.1.6.el5 #1
> The X-Term is diskless, boots via PXE from a Solaris 10 box. Diskless boot configured using stock Cent tools (system-config-diskless and friends)
> 
> Any suggestion where to look would be appreciated.
> 


Had any updates to xorg-x11-server-Xorg recently on the affected systems 
as that can make changes to xorg.conf?

Also, how are you handling nvidia.ko over kernel updates? Could a reboot 
have booted to a new kernel, xorg failed due to nvidia.ko not matching 
the present kernel, and reconfigured to use nv? Using the elrepo kmod 
driver or rpmforge dkms nvidia driver would alleviate this.