Forum / NoMachine for Linux / Resizing of a headless session
Tagged: headless resolution
- This topic has 5 replies, 4 voices, and was last updated 7 years, 3 months ago by Tor.
January 26, 2016 at 09:41 #9777mkriskParticipant
I am trying NoMachine 5 (free version for Linux) running on a headless debian server. When I enable the “Resize remote screen” option and do some resizing, I sometimes get black bars on borders of the window. I do understand that normally the “physical” session mode doesn’t allow setting an arbitrary resolution. But is it also supposed to be the case when running NoMachine in the “headless” mode for physical desktop ?
I don’t get this problem if I try a virtual session mode on NoMachine Workstation Evaluation.January 29, 2016 at 20:29 #9891fra81Moderator
as you noted, on headless machines it should be possible to set any resolution. We are trying to reproduce your issue in our labs. We will be back to you!February 3, 2016 at 11:18 #9937TorParticipant
could you please confirm you see black borders when the client window is at its minimum size, so you cannot make it smaller?February 8, 2016 at 08:55 #9989Steve973Participant
Hello. If I may add to this discussion, I think I can explain the problem that @mkrisk is having. I am using Ubuntu version 15.10 with Mate as the window manager and lightdm as the display manager. When Ubuntu starts, it creates an x session and, since there is no monitor connected, it has no idea what modes are supported to whatever display will connect to it. So it starts with a fixed resolution of whatever the window manager defaults to, I believe. In my case, it seems to be 1024×768. So, to reproduce the problem, you might try creating a headless installation with a configuration like I described. Whether or not it matters, I am using an Intel NUC5i5RYH with an Intel HD 6000 display chip, and I believe that the driver module that it uses is the i915.
I have read that you can install the xserver-xorg-video-dummy driver and create an xorg.conf file that contains a device section that specifies the dummy xorg driver, a monitor section that sets sync and refresh, and finally, a screen section that uses the defined monitor and driver, and specifies the modes that you want to be able to use. This is described at http://askubuntu.com/questions/453109/add-fake-display-when-no-monitor-is-plugged-in if you want to read about it in more detail.
I tried this configuration, and it kind of worked, but it resulted in some errors in Mate when I was running it. I also do not like to create a static configuration reminiscent of fifteen years ago, because it would be nice if we could get this working in the dynamic way that the x server currently operates under normal circumstances.
A nice solution would be to provide a way that allows the x server to be initialized properly when run headless without having to specify a specific configuration. That way, if we want to connect a keyboard, mouse, and monitor to our headless servers, it will work properly that way, and at other times (which is the majority of the time) we can run our servers in a headless configuration and have NoMachine be able to adjust the resolution through the NoMachine client.
I hope this helps, and I’m very interested in seeing a solution. Thanks for your time!
SteveFebruary 9, 2016 at 10:39 #10007Steve973Participant
I also tried using a monitor “dongle” that plugs into the HDMI port. It allows the graphics card to initialize, and it makes Linux think that there is a 4K monitor attached, and I can select some modes. It isn’t perfect, but it allows resolution that is better than 1024×768, even if the modes aren’t the ones that are exactly native to my display.February 17, 2016 at 19:43 #10123TorParticipant
You may try to switch off your X server and let NoMachine create the virtual display for you. Switch to runlevel 3 or stop lightdm, and create a connection to that desktop. Visit this link for more information about the configuration:
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