[HowTo] Install a vnc server on the Raspberry pi

fzinken · 20 November 2020 11:50

I haven’t tried myself so can not say if there is a problem with the script as all steps looked to work. So maybe it was just user problem.

Chuff · 19 April 2021 02:41

This webpage has been a godsend for me for every installation of OSMC I have had and it has always worked perfectly until now.

I recently bought a Pi4 and have just installed the beta installation of OSMC for Pi4 and have been unable to get VNC to work.

Everything seems to install correctly but I cannot connect.

Connecting via SSH to my old Pi3 and running telnet 127.0.0.1 5900 shows that the service is running and I can connect locally, however, on the Pi4 running the same telnet command returns the following:

Trying 127.0.0.1…
telnet: Unable to connect to remote host: Connection refused

Short of this I don’t know what else to do to test that the service is working correctly. Checking services shows that openvpn is installed and running as a service.

Any help appreciated. If you would like me to do further tests/checks please ask. I’m not a novice at Linux but I’m in no way an expert so please be kind.

Thanks.

fzinken · 19 April 2021 02:51

The Pi Videostack changed and this method will not work until a new VNCserver solution is used.

Chuff · 19 April 2021 03:02

Thanks for the quick reply fzinken.

I’ll keep an eye on this thread for any future updates.

Peace.

the_bo · 29 April 2021 16:48

Hopefully a solution can be found as need access pi4 screen from another room.

patrikolausson · 30 April 2021 16:30

The following works for me.

in /boot/config.txt, change the line
dtoverlay=vc4-kms-v3d,cma-512
to
dtoverlay=vc4-fkms-v3d,cma-512

Set the resolution to maximum 1080p.

I have no idea if kms/fkms breaks anything else or e.g. affects performance. For higher resolutions than 1080p I fail to get a snapshot, and need to do a hard reboot to get it working again.

the_bo · 30 April 2021 17:30

Didn’t work for me with change. Says connection refused.

Here is my config:

[pi4]
dtoverlay=rpivid-v4l2
arm_64bit=1
kernel=kernel.img

[all]
dtoverlay=vc4-fkms-v3d,cma-512
disable_overscan=1
start_x=1
disable_splash=1
disable_fw_kms_setup=1
include config-user.txt

dillthedog · 30 April 2021 20:29

Didn’t work for me with dtoverlay=vc4-fkms-v3d,cma-512. When run from the command line it fails:

osmc@osmc:~$ sudo /usr/bin/dispmanx_vncserver
2021-04-30 20:25:25.153 [dmxvnc] Trying to read configuration file: /etc/dispmanx_vncserver.conf
2021-04-30 20:25:25.154 [dmxvnc] Read config file: /etc/dispmanx_vncserver.conf
2021-04-30 20:25:25.155 [dmxvnc] Running vnc server with the following settings
	frame-rate = 15
	downscale = false
	fullscreen = false
	localhost = false
	multi-threaded = false
	password = ***
	port = 5900
	relative = false
	screen = 0
	unsafe = false
	vnc-params = 
2021-04-30 20:25:25.158 [dmxvnc] Open display[0]...
2021-04-30 20:25:25.159 [dmxvnc] Exception: vc_dispmanx_display_open failed

The Pi4 isn’t connected to a TV.

patrikolausson · 1 May 2021 08:23

I now tried it all from the start, just to make sure I had not forgot about anything I did to make it work.

Flashed the OSMC_TGT_rbp4_20210414.img.gz image
Boot with hdmi connected (osmc did not seem to install without)
Wait for install
Followed Sandbird’s Step1 in the first post
“sudo ./dispmanx_vncserver” : resulted in “2021-05-01 07:51:28.109 [dmxvnc] Exception: vc_dispmanx_display_open failed”
Changed from vc4-kms-v3d to vc4-fkms-v3d in /boot/config.txt
Reboot
“sudo ./dispmanx_vncserver” : no error after “2021-05-01 07:58:15.735 [dmxvnc] Open display[0]…”
Connect with VNC client : dispmanx_vncserver throws error on snapshot: “2021-05-01 07:58:21.283 [dmxvnc] Caught exception: vc_dispmanx_snapshot failed”
The VNC client is stuck on connecting, no screen showing
Not possible to kill dispmanx_vncserver.
Recycled power
Changed resolution in osmc to 1080p
“sudo ./dispmanx_vncserver” : no errors
Connect with VNC client works

Also tried without a TV/monitor connected

Disconnect hdmi
Reboot
“sudo ./dispmanx_vncserver” : resulted in 2021-05-01 08:16:44.104 [dmxvnc] Exception: vc_dispmanx_display_open failed
added hdmi_force_hotplug=1 to /boot/config.txt
Reboot
“sudo ./dispmanx_vncserver” : ok
VNC client works, osmc limited to max 1024x768 (I have not been able to set any combination of hdmi_group and hdmi_mode to get a higher resolution yet)

fzinken · 1 May 2021 10:06

Can confirm this works

This is most likely the big question. But some quick test didn’t reveal issues.
Performance also looks good. Not sure what happens on 4k.

sam_nazarko · 1 May 2021 10:12

patrikolausson · 1 May 2021 16:22

I have a few use cases where remote access is really practical. I will most likely use this config from time to time when needed, and do not recommend anyone to use this as a permanent solution. Unfortunately I have not been able to figure out how to get a snapshot of the display with the new drivers. I would be thankful if someone has some ideas how to replace dispmanx for the vnc server.

the_bo · 1 May 2021 16:39

Sam can you describe why this shouldn’t be changed?

sam_nazarko · 1 May 2021 18:01

I haven’t looked in detail, but TigerVNC might be the way forward, as it seems to support DRM backends.

joakim_s · 1 May 2021 22:47

I think you should look into “DRM Writeback connector”, I did peek at it but it quickly went over my head.

htpcero · 30 July 2021 23:15

@everyone anybody got tigervnc server to work on RPI4/osmc?
I will also miss having remote graphical access for the occasional remote configuration change
p.s. I’d rather not change the video driver

fzinken · 31 July 2021 01:38

That is currently the only way to do it

tRoller · 30 August 2021 18:40

my PI3 crashed (again) and I did a fresh installation. The first thing I usually install is vnc server so I don’t have to plug in a keyboard and mouse for the basic set up.

After installation - I can’t get the vnc server to start.

osmc@osmc:~$ service dispmanx_vncserver status
* dispmanx_vncserver.service - VNC Server
   Loaded: loaded (/etc/systemd/system/dispmanx_vncserver.service; enabled; vendor preset: enabled)
   Active: activating (auto-restart) (Result: exit-code) since Mon 2021-08-30 18:27:23 UTC; 17s ago
  Process: 1586 ExecStartPre=/sbin/modprobe evdev (code=exited, status=0/SUCCESS)
  Process: 1587 ExecStart=/usr/bin/dispmanx_vncserver (code=exited, status=1/FAILURE)
 Main PID: 1587 (code=exited, status=1/FAILURE)

If I run it manually, this is what I get:

osmc@osmc:/usr/bin$ ./dispmanx_vncserver 
2021-08-30 18:37:45.986 [dmxvnc] Trying to read configuration file: /etc/dispmanx_vncserver.conf
2021-08-30 18:37:45.987 [dmxvnc] Read config file: /etc/dispmanx_vncserver.conf
2021-08-30 18:37:45.988 [dmxvnc] Running vnc server with the following settings
        frame-rate = 15
        downscale = false
        fullscreen = false
        localhost = false
        inetd = false
        multi-threaded = false
        once = false
        password = ***
        port = 5900
        relative = false
        screen = 0
        unsafe = false
        vnc-params = 
2021-08-30 18:37:45.992 [dmxvnc] Open display[0]...
2021-08-30 18:37:45.994 [dmxvnc] Exception: vc_dispmanx_display_open failed

I tried rebooting, removing and reinstalling.

Thanks in advance.

fzinken · 31 August 2021 00:34

In the moment this is the only fix if you need VNC

tRoller · 2 September 2021 18:03

Is this for RPi3 aswell or for RPi4 only?