mirror of
https://github.com/QubesOS/qubes-doc.git
synced 2024-12-22 05:55:05 -05:00
114 lines
4.2 KiB
ReStructuredText
114 lines
4.2 KiB
ReStructuredText
===================
|
||
GUI troubleshooting
|
||
===================
|
||
|
||
|
||
Can't click on anything after connecting 4k external display
|
||
------------------------------------------------------------
|
||
|
||
|
||
When you connect a 4K external display, you may be unable to click on
|
||
anything but a small area in the upper-right corner.
|
||
|
||
When a qube starts, a fixed amount of RAM is allocated to the graphics
|
||
buffer called video RAM. This buffer needs to be at least as big as the
|
||
whole desktop, accounting for all displays that are or will be connected
|
||
to the machine. By default, it is as much as needed for the current
|
||
display and an additional full HD (FHD) display (1920×1080 8 bit/channel
|
||
RGBA). This logic fails when the machine has primary display in FHD
|
||
resolution and, after starting some qubes, a 4K display is connected. If
|
||
the buffer is too small, and internal desktop resize fails.
|
||
|
||
The solution to this problem is to increase the minimum size of the
|
||
video RAM buffer, as explained in :ref:`GUI Configuration <user/advanced-topics/gui-configuration:video ram adjustment for high-resolution displays>`.
|
||
|
||
Screen blanks / Weird computer glitches like turning partially black or black boxes
|
||
-----------------------------------------------------------------------------------
|
||
|
||
|
||
You may encountering seemingly random screen blanking while using Qubes,
|
||
where the screen will black and shows the logon screen, yet, only the
|
||
active window will show when you move the mouse or use the keyboard.
|
||
Sometimes, you will get random black screens or black boxes.
|
||
|
||
Similarly, while working, the XScreenSaver dialog may pop up (indicating
|
||
the screen is locked) and the screen goes black. However, the screen is
|
||
not locked, and you have to move a window to redraw the screen.
|
||
|
||
If you are experiencing the any of the above symptoms, try disabling the
|
||
window compositor:
|
||
|
||
``Q → System Tools → Window Manager Tweaks → Compositor → uncheck “Enable display compositing”``
|
||
|
||
Post installation, screen goes black and freezes following LUKS decryption
|
||
--------------------------------------------------------------------------
|
||
|
||
|
||
After installing Qubes, you may experience a black screen after entering
|
||
your LUKS decryption password. To fix the problem, use your preferred
|
||
text editor (``nano`` works) to edit
|
||
``/mnt/sysimage/boot/efi/EFI/qubes/xen.cfg``, adding the ``efi=no-rs``
|
||
option to the end of the ``options= line``. For example:
|
||
|
||
.. code:: bash
|
||
|
||
[4.14.18-1.pvops.qubes.x86_64]
|
||
options=loglvl=all dom0_mem=min:1024M dom0_mem=max:4096M iommu=no-igfx ucode=scan efi=no-rs
|
||
|
||
|
||
|
||
Note that the ``/mnt/sysimage/boot/efi/EFI/qubes/xen.cfg`` path applies
|
||
when running from the installer (either directly after installation,
|
||
before the reboot, or by starting the installer again in recovery mode).
|
||
On the actual installed system, the file to edit is
|
||
``/boot/efi/EFI/qubes/xen.cfg`` – but it may be hard to access directly
|
||
when your system won’t boot.
|
||
|
||
Can start VM, but can't launch any applications
|
||
-----------------------------------------------
|
||
|
||
|
||
If you can start your VM, but can’t launch any applications, then you
|
||
need to fix the issues from the ``VM console``, accessible from xen
|
||
through:
|
||
|
||
.. code:: bash
|
||
|
||
qvm-start <VMname> # Make sure the VM is started
|
||
qvm-console-dispvm <VMname>
|
||
|
||
|
||
After launching a VM console using ``qvm-console-dispvm``, you may look
|
||
at the ``qubes-gui-agent`` service state with:
|
||
|
||
.. code:: bash
|
||
|
||
systemctl status -l qubes-gui-agent
|
||
|
||
|
||
|
||
If the service is in a failed state, you should see some messages on why
|
||
it failed.
|
||
|
||
Another helpful place to look into is ``/home/user/.xsession-errors``,
|
||
which may also contain some hints what is wrong.
|
||
|
||
Disable audited messages
|
||
^^^^^^^^^^^^^^^^^^^^^^^^
|
||
|
||
|
||
During troubleshooting, you may be getting a lot of ‘audit’ messages
|
||
which make the log very noisy. To disable audited messages, you need to
|
||
edit your VM kernel parameters:
|
||
|
||
.. code:: bash
|
||
|
||
previous_kernel_parameters=$(qvm-prefs --get <VMname> kernelopts) # Get current kernel parameters
|
||
qvm-prefs --set <VMname> kernelopts "<previous_kernel_parameters> audit=0"
|
||
|
||
|
||
Then, restart your VM.
|
||
|
||
Once your troubleshooting is done, don’t forget to remove this kernel
|
||
parameters, it makes troubleshooting VMs not starting easier.
|