Mirrored display broken in Xubuntu

[Omadas]

Mirrored displays is not accessible (grayed out) when trying to activate this feature for multi-monitor support. I am not sure which specific package to nominate for this bug, but it seems to only be happening on systems with XFCE4 installed and running (Including Xubuntu, Mint, and Debian).

It maybe an error with the package xfce4-display-settings, but I am not sure.

This bug is being reported from:
Description: Linux Mint 17.2 Rafaela
Release: 17.2

Here is a copy of this Bug Report on Bugzilla: https://bugzilla.xfce.org/show_bug.cgi?id=11712
This bug report also has a picture attachment which is exactly what I am seeing.

[Blt2i4b72d (blt2i4b72d)]

Created attachment 6088
Mirror Displays bug

After upgrading Xfce 4.10 to 4.12, "Mirror Displays" (xfce4-display-settings --minimal) appears disabled.

The command "xrandr --output HDMI-0 --auto --same-as DVI-I-1" works as before.

So, yes, it's a Xfce bug.

xorg-xrandr 1.4.3
libxrandr 1.4.2

[netllama (netllama)]

Just upgraded to 4.12, and I'm hitting this bug as well. Any chance of a work around or fix in the near future (this bug has been open for nearly 8 months)?

[Omadas (bsperger)]

Yes. There are a few work a rounds. I will try to post directions that will tell you what command to use to marrow when I have my laptop. Sorry for the wait.

[autumna (autumna)]

Probaby one of the most beginner friendly workarounds to this is to use ARandR which is a gui for XRandR, and allows arrangement and enabling/disabling of displays manually.

sudo apt-get update
sudo apt-get install arandr
(or alternatively use your package manager/software installer of choice)

You can find ARandR in the system settings, if not just start it from the terminal. You can arrange your screens the way you want them.

[autumna (autumna)]

ok intel graphics user doesn't have this problem so it seems it is potentially occurs with nvidia graphic cards. (both with nouveau and nvidia proprietary drivers). Added those packages to the issue.

[penalvch (penalvch)]

Omadas, thank you for taking the time to report this and trying to help make Ubuntu better. However, Linux Mint is not a software package provided by the official Ubuntu repositories. Because of this the Ubuntu project can not support or fix your particular bug. Please report this bug to the provider of the software package. Thanks!

If you are interested in learning more about software repositories and Ubuntu, check https://help.ubuntu.com/community/Repositories.

[Guest (disposable-s)]

I can confirm this bug in Xubuntu 16.04 (xfce version 4.12) with a dedicated graphics adapter (using the proprietary nvidia kernel module).

In my opinion, the importance is not medium as it produces serious trouble when working with a docking station.

I either work at home, the laptop lid closed and the laptop docked in the docking station.
There is an external monitor connected to the docking station.

Mirroring both the laptop and external monitor is not possible due to this bug.
When I wake up the laptop from suspend to ram, the laptop is the primary monitor, but the lid is closed. The external monitor is not powered up.
Then I have to open the lid, log in, reconfigure the external monitor again and can then close the lid.
The laptop is right below my external monitor. There is no space to have both monitors active.

I already tried having the external monitor the primary monitor.
Then I run into another problem when taking the laptop with me.
When woke up on the go, the laptop display is not activated. Instead it stays powered off.
It looks like the no longer available external monitor is still the primary monitor.

What about this suggestion:
Set all unconfigured monitors to mirrored instead of off. This way there is a good chance to get access to the graphical user interface again.

N.B. I do not know why, but in 14.04 xrandr could not be used from a console, although xorg cookies and display variables were set correctly.

[Guest (disposable-s)]

Nvidia-package: nvidia-graphics-drivers-304 (Ubuntu).

[penalvch (penalvch)]

Guest (disposable-s), it will help immensely if you filed a new report with Ubuntu by ensuring you have the package xdiagnose installed, and that you click the Yes button for attaching additional debugging information running the following from a terminal:
ubuntu-bug xorg

Also, please feel free to subscribe me to it.

For more on why this is helpful, please see https://wiki.ubuntu.com/ReportingBugs.

[Saúl (seaguila91)]

I use Ubuntu Studio 16.04 with XFCE4 4.12 and I had that problem too, but exploring the "Extend to the right" option and then returning to "Displays", "Mirror Displays" option is already accessible. Unfortunately, unplugging the another monitor and plugging it again, may recquire select first "Extend to the right" to make "Mirror Displays" accesible again.

[Sam Fite (fitesam98)]

I am using xfce 4.12 on Ubuntu 18.04 and am having a similar issue. However, on startup, my laptop screen is mirrored on the intended external monitor just before I reach lightdm. xrandr detects the monitor however running 'xrandr --output <> --same-as <>' results in no effect with no error messages or anything. When viewed through xfce4-settings-manager, the external monitor shows up but is grayed out and is labeled '(disabled);

[milanbb55 (milanbb55)]

For everyone who has the same problem, this solution https://unix.stackexchange.com/questions/371793/how-to-duplicate-desktop-in-linux-with-xrandr/371796 worked for me.