New Monitor Weirdnesses or how do I get Xorg to pay attention to my xorg.conf file?

Ron Wheeler rwheeler at
Sat Dec 5 18:48:17 PST 2015

On 04/12/2015 9:06 PM, Robert Heller wrote:
> At Fri, 4 Dec 2015 15:11:33 -0500 xorg at wrote:
>> I am just using the KVM included in CentOS7 with Cloudstack.
>> Not sure what I am missing by not including Xen but I am pretty new at it.
> CentOS 5 predates KVM and used Xen for virtualization. CentOS 6 and 7 include
> KVM for virtualization and don't use a Xen hypervisor. You are not 'missing'
> anything: Xen is just the older virtualization hypervisor.
That is what I suspected. Thanks to the reassurance.
>> I can not help but believe that CentOS 7 would be a better platform for
>> virtualization than CentOS 5.
>> CentOS 7 is not too bad but it is different and it has taken me a while
>> to stop fighting it.
> I don't want to take that step until I have learned to deal with the likes of
> systemd, etc.  I install CentOS 6 as the host and install CentOS 7 in a VM, to
> have a standbox to learn in, and still be able to get work done.
Sounds like a good plan.
I just jumped in with a couple of  spare physical machines to see if I 
could get Centos 7 to production quality/use in key roles.
I was able to build the systems and test them with the ability to drop 
the old system back in if it did not work.

>> The changes to networking and the firewall were hard to absorb. The new
>> way to manage processes is still a bit of a challenge for me but I am
>> not spending any time on this since it works just fine.
>> I run a software firewall, DNS server and virtual router which I moved
>> from CentOS 4 to CentOS 7 and it seems to work better but it is hard to
>> tell if it is the newer hardware or the new OS. This is a critical part
>> of the infrastructure and I am happy with the change.
>> The hardware was too old to run the nouveau driver properly so I am
>> running the NVIDIA legacy driver. Works but I am not using it as a
>> workstation.
>> Ron
>>    On 04/12/2015 12:43 PM, Robert Heller wrote:
>>> At Fri, 4 Dec 2015 11:42:18 -0500 xorg at wrote:
>>>> If you ready for some fun, CentOS 7 is out and into its third revision.
>>>> Did I miss the discussion about the drivers from NVIDIA? I am using them
>>>> with new and old hardware(different machines).
>>>> A bit tricky to get working and there are different drivers for legacy
>>>> cards and newer cards.
>>> The drivers from NVIDIA are not supported for Xen-based systems.  I am using
>>> Xen for virtualization, so the drivers from NVIDIA are not an option.
>>> Appearently the kernel and Xorg that sh
>>>> I had trouble with the nouveau driver but it may have been me or may
>>>> have been an early version.
>>> The nouveau driver is not available for CentOS 5 -- the kernel and Xorg
>>> libraries are too old.
>>>> CentOS 7 runs well but it does have a lot of changes to the tools that
>>>> one got used to in CentOS 5 and 6.
>>> *I* am not ready for that big a change.  It would probably be too disruptive
>>> for my work flow.  I *may* install CentOS 7 as a VM at some point.
>>>> It is supposed to be a better workstation OS.
>>>> I am still running 5 and 6 on some production machines.
>>>> I am not using my units as workstations but like to have the GUI working
>>>> well in case I have some maintenance activities that are easier in the GUI.
>>>> Ron
>>>> On 04/12/2015 10:30 AM, Robert Heller wrote:
>>>>> At Fri, 4 Dec 2015 12:32:59 +1000 Dave Airlie <airlied at> wrote:
>>>>>> On 4 December 2015 at 12:27, Robert Heller <heller at> wrote:
>>>>>>> At Thu, 3 Dec 2015 16:27:22 -0500 Felix Miata <mrmazda at> wrote:
>>>>>>>> Robert Heller composed on 2015-12-03 16:00 (UTC-0500):
>>>>>>>>> I use a distro with long term support.
>>>>>>>> Not without a price. What you have is hardware technology that is more
>>>>>>>> advanced than the foundation on which that support is built. A GeForce 8200
>>>>>>>> needs either the FOSS nouveau driver, which seems to be missing from CentOS
>>>>>>>> 5, or the proprietary NVidia driver. VESA is a low technology fallback driver
>>>>>>>> wholly incapable of properly supporting widescreen displays. AFAICT, there's
>>>>>>>> no amount of xorg.conf or xrandr twiddling you can do to overcome the
>>>>>>>> shortcomings of a fallback driver.
>>>>>>> The video chipset has been working fine with the CentOS software, with a 4:3
>>>>>>> monitor. The (available) proprietary NVidia driver won't work with a Xen
>>>>>>> kernel.
>>>>>> The graphics card BIOS contains the modes that vesa can use. It doesn't have
>>>>>> widescreen modes in it. The below 3 choices are yours.
>>>>>> CentOS6 should drive things better in theory.
>>>>> I guess I will have to upgade to CentOS 6...
>>>>>> Dave.
>>>>>>>>>     *I* have better things to do than
>>>>>>>>> spend all of my time dealing with incompatible updates every few months.
>>>>>>>> You have 3 choices that I can see:
>>>>>>>> 1-upgrade software to the technology level of your hardware (nouveau driver,
>>>>>>>> likely requiring KMS kernel)
>>>>>>>> 2-backlevel your video hardware (either supported gfxcard, or supported 4:3
>>>>>>>> or 5:4 aspect display)
>>>>>>>> 3-suffer a standard aspect video mode on your widescreen display

Ron Wheeler
Artifact Software Inc
email: rwheeler at
skype: ronaldmwheeler
phone: 866-970-2435, ext 102

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