Disable LVDS Display on CentOS
<p>I have a kind of a weird problem, let me try to explain it:</p>

<p>I got CentOS 7 installed and I'm running a desktop environment on it (using it as a display to show a website on it, nothing big). Now when I boot it, it has 2 displays, one is the LVDS display, the other one is my hardware display, connected via VGA to a normal monitor</p>

<p>The problem here is that the monitor only shows the background, the LVDS seems to be the primary display. Now, I'm not that much into Linux but I know how to set the VGA display to primary.</p>

<pre><code>xrandr --output VGA --primary
</code></pre>

<p>When I execute that command it tells me "Can't open display"
Same for using 'xrandr' only to show all displays</p>

<p>Now, this is the twist: When I'm on the desktop environment, I can't open any terminals. When I'm inside the VT (via CTRL+ALT+F3) xrandr seems to fail open the displays.</p>

<p>How else can I change the VGA display to primary? I even tried switching to HDMI or plugging in a 2nd monitor.</p>

<p>Any ideas?</p>