said Peter Laws: | CentOS 7 current, TDE current. Nvidia Quadro M2000 (4 x DP out), 2 x | Dell P2416D displays. | | Applied patches last week and one of them (that seemed to be related | to the Nvidia proprietary drivers) blew up the system. Eventually | ended up re-installing in an ultimately-failed bid to get productive | again (this is my work system). | | Decided to forgo the Nvidia drivers and use the open source stuff. | Xrandr is a nightmare though, so I thought "well, just use the TDE | built-in screen controls". | | Problem is that System Settings -> Monitor & Display can only see one | of the displays. How do I get it to see the 2nd display? | | Yes, it's plugged in. Yes, I've checked "Enable global display | control". Yes, I've clicked "Rescan Displays" (many times). "Test | Settings" gets me "xrandr: Failed to get size of gamma for output | default". | | Not sure the system is seeing the first display correctly even though | it's working (I am typing this message on it) because while is sees | 2560 x 1440 pixel, it thinks the refresh rate is 0 Hz (though, again, | its working). | | Do I have to create and edit an Xorg.conf? Because I tried that and | it didn't go well not to mention defeating the purpose of a "settings" | GUI ... I encountered much the same thing, also with a Nvidia vid card, just recently. Like you, I got no satisfaction with the Monitor & Display setting in KControl, which also failed to see one of my two monitors. I ended up installing, again, the current Nvidia driver for my card, and the Nvidia control application. Then I went in the Nvidia app to "X Server Display configuration" where both monitors were seen. I was able to configure them as to their relative position and so on. That having been said, there *is* a little voodoo to it, but it gives you something that if fiddled with will ultimately work. -- dep The shortest distance between you and playing great acoustic guitar: the great new instructional DVDs from Marjorie Thompson, available at www.MarjorieThompson.com

Peter Laws composed on 2017-08-14 11:41 (UTC-0500): ... 1-arandr should configure specific to each individual user running TDE 2-xrandr in a startup script can configure either to one user or globally 3-xorg.conf* can do the same as xrandr in a startup script 4-screen configuration in TDE Control Center has been reported to be functional in recent weeks here. What does xrandr in a terminal report? Is there a firmware package for NVidia hardware that needs to be installed? Do either 'dmesg | grep fail' or 'systemctl | grep fail' provide clues? The nouveau Xorg driver is a separate package. The modesetting driver is integrated in 1.17.x+ servers. Fedora and Debian not terribly long ago changed the default for NVidia hardware to using the modesetting driver. In any event, Xorg should be using the modesetting automatically if neither NVidia nor Nouveau drivers are installed, if the NVidia hardware is not too new to be supported. According to Wikipedia, the M2000 was released 2016-04-08. CentOS 7 provides server 1.17.2, which is older, and kernel 3.10, which is much older. The OP reports your system had been working with proprietary NVidia drivers. Could it be that that was because required M2000 support in FOSS hadn't been backported to CentOS7? -- "The wise are known for their understanding, and pleasant words are persuasive." Proverbs 16:21 (New Living Translation) Team OS/2 ** Reg. Linux User #211409 ** a11y rocks! Felix Miata *** http://fm.no-ip.com/

Peter Laws wrote: Hi there, I use debian and no NVid, so I can't tell much regarding to this, except that I recall a similar nightmare experience couple of years ago, just had to learn how this opengl thing relates to all of that. On the debian (mostly dell notebooks with intel card) I had to create my own xorg.conf to initialize the displays. After this, I can handle it via xrandr or the controls. If using the proprietary NVid driver, you may need to look into the specific settings, but hey, once it works it works forever (or until you break it). regards