I would like to start a new Xorg server on a **remote** host. At first, I tought this would be as easy as it is on the local host: $ xinit /usr/bin/startxfce4 -- :4 On a _local_ host, this command typed into a (non-graphic) login shell (vt/tty) will start _another_ Xorg server, i.e. I will have a xfce4 desktop after this - and this desktop is _additional_ to my normal desktop started from login from the desktop manager (e.g. sddm). However, if I try that on a _remote_ (fedora) system from the ssh console: X.Org X Server 1.20.6 X Protocol Version 11, Revision 0 Build Operating System: 5.0.6-200.fc29.x86_64 Current Operating System: Linux noah.siteos-lokal.de 5.5.10-200.fc31.x86_64 #1 SMP Wed Mar 18 14:21:38 UTC 2020 x86_64 Kernel command line: BOOT_IMAGE=(hd0,msdos3)/vmlinuz-5.5.10-200.fc31.x86_64 root=/dev/mapper/vg_sdd-root ro rd.luks.uuid=luks-a9eba963-ff2e-499b-a298-0659c5e29359 rd.lvm.lv=vg_sdd/root rd.lvm.lv=vg_sdd/swap rhgb quiet resume=/dev/disk/by-uuid/73299393-6bdb-4230-a1ca-096e5ee32396 splash=silent quiet video.use_native_backlight=1 Build Date: 25 November 2019 12:00:00AM Build ID: xorg-x11-server 1.20.6-1.fc31 Current version of pixman: 0.38.4 Before reporting problems, check http://wiki.x.org to make sure that you have the latest version. Markers: (--) probed, (**) from config file, (==) default setting, (++) from command line, (!!) notice, (II) informational, (WW) warning, (EE) error, (NI) not implemented, (??) unknown. (==) Log file: "/home/tpasch/.local/share/xorg/Xorg.4.log", Time: Fri Apr 3 19:38:52 2020 (==) Using config directory: "/etc/X11/xorg.conf.d" (==) Using system config directory "/usr/share/X11/xorg.conf.d" (EE) Fatal server error: (EE) parse_vt_settings: Cannot open /dev/tty0 (Permission denied) (EE) (EE) Please consult the Fedora Project support at http://wiki.x.org for help. (EE) Please also check the log file at "/home/tpasch/.local/share/xorg/Xorg.4.log" for additional information. (EE) (EE) Server terminated with error (1). Closing log file. xinit: giving up xinit: unable to connect to X server: Connection refused xinit: server error I wonder why it is possible to start _another_ Xorg on the _local_ host but I get this error on a _remote_ host. I'm _not_ expecting to 'see' the new desktop from my ssh terminal. But I would expect that I could ‘export’ the new Xorg rendered desktop with e.g. x11vnc. It there easy way to get this running? The bounty is for: * Showing how to start _another_ Xorg server on a _remote_ fedora machine from a ssh terminal session. The following answers will not be considered: * Using Xvfb, Xvnc or the like. * Using some kind of remote desktop technology (RDP, VNC, Spice, TeamViewer, ...)

I was following the steps from this link- Kali In The Browser (noVNC) I have installed kalilinux/kali-rolling on docker and running the commands. When I execute the command x11vnc -display :0 -autoport -localhost -nopw -bg -xkb -ncache -ncache_cr -quiet -forever I am getting the following error. > 22/03/2022 11:10:08 *************************************** 22/03/2022 11:10:08 *** XOpenDisplay failed (:0)
*** x11vnc was unable to open the X DISPLAY: ":0", it cannot continue.
*** There may be "Xlib:" error messages above with details about the failure.

Some tips and guidelines:
** An X server (the one you wish to view) must be running before x11vnc is started: x11vnc does not start the X server. (however, see the -create option if that is what you really want).
** You must use -display , -OR- set and export your $DISPLAY environment variable to refer to the display of the desired X server.
- Usually the display is simply ":0" (in fact x11vnc uses this if you forget to specify it), but in some multi-user situations it could be ":1", ":2", or even ":137". Ask your administrator or a guru if you are having difficulty determining what your X DISPLAY is.

** Next, you need to have sufficient permissions (Xauthority) to connect to the X DISPLAY. Here are some Tips:
- Often, you just need to run x11vnc as the user logged into the X session.
So make sure to be that user when you type x11vnc.
- Being root is usually not enough because the incorrect MIT-MAGIC-COOKIE file may be accessed. The cookie file contains the secret key that allows x11vnc to connect to the desired X DISPLAY.
- You can explicitly indicate which MIT-MAGIC-COOKIE file should be used by the -auth option, e.g.: x11vnc -auth /home/someuser/.Xauthority -display :0 x11vnc -auth /tmp/.gdmzndVlR -display :0you must have read permission for the auth file. See also '-auth guess' and '-findauth' discussed below.

** If NO ONE is logged into an X session yet, but there is a greeter login program like "gdm", "kdm", "xdm", or "dtlogin" running, you will need to find and use the raw display manager MIT-MAGIC-COOKIE file. Some examples for various display managers:

gdm: -auth /var/gdm/:0.Xauth -auth /var/lib/gdm/:0.Xauth kdm: -auth /var/lib/kdm/A:0-crWk72 -auth /var/run/xauth/A:0-crWk72 xdm: -auth /var/lib/xdm/authdir/authfiles/A:0-XQvaJk dtlogin: -auth /var/dt/A:0-UgaaXa > Sometimes the command "ps wwwwaux | grep auth" can reveal the file location. Starting with x11vnc 0.9.9 you can have it try to guess by using: -auth guess (see also the x11vnc -findauth option.)
Only root will have read permission for the file, and so x11vnc must be run as root (or copy it). The random characters in the filenames will of course change and the directory the cookie file resides in is system dependent. See also: http://www.karlrunge.com/x11vnc/faq.html From this, I will get the answer - https://www.linuxquestions.org/questions/linux-software-2/x11vnc-at-startup-4175414461/ . But I can't understand what they saying

I need to access a remote machine via a high latency, slow connection. It uses x11vnc and I want it to broadcast video in much lower quality than what's actually on the screen. First thing that comes to mind is to use less colours (e.g. 8 bit), but it can be anything, as long as the remote machine is responsive even though it may, for example, show a large rich-colour desktop image (which I don't need to see anyway). Something [like this](https://superuser.com/questions/411058/setting-up-tightvnc-for-8-bit-pixels) , except for x11vnc. I will, however, appreciate keeping all the text sharp because, I work with the terminal. Here's what I tried: - use -notruecolor, found here http://www.karlrunge.com/x11vnc/x11vnc_opts.html - use -speeds dsl, found here https://ubuntuforums.org/showthread.php?t=1331555 - try setting 8 bit video using -rawfb, found here https://linux.die.net/man/1/x11vnc - enable -ncache 10 as per https://feeding.cloud.geek.nz/posts/high-latency-vnc-tech-support/ , but got [this issue](https://github.com/novnc/noVNC/issues/525) I'm using the built-in Screen Sharing app, which [seems to be almost the only option](http://web.archive.org/web/20180324015551/http://www.davidtheexpert.com/post.php?id=5) on Mac OS. I'm out of ideas. Please help.

I am trying to set up a vnc connection between 2 computers, but am having trouble so far. In order to **understand the concept**, I am now simply trying to start a vnc server (using x11vnc) and connect to it using ssvnc **on the same computer** This page supposedly explains how to do so. Apparently, starting a vnc server should be as simple as downloading x11vnc and using the command x11vnc -display :0 The same page also contains a link to download ssvnc, that can be used as a vnc client (link here for your convenience ) It states that in order to connect using the vnc client, suffice to unpack the tar.gz directory, then run ./ssvnc/Unix/ssvnc. Then, I start ssvnc and type in user@localhost such as follow: However when i press connect, a xterm windows appears, with the following message: The x11vnc docs mentions that a common gotcha is to set the Xauth - I tried to do that by re-running the server with x11vnc -display :0 -auth /home/user/.Xauthority But I received the same error message. Anyone can help me out here with that basic test / problem?

I submit defeat. I have been trying to configure my remote Linux box to have two dummy monitors so that I can use multiple local monitors to VNC into it. I'm surprised that no one else has needed help with this to find something on the web. I've also tried creating a monitor on the Linux box that is double wide. Then use x11vnc to -clip an area for each display. But I'm having issues creating a monitor that large with the dummy driver. I do have a graphics adapter installed that has two DisplayPorts but am not planning to use it. When I was using the real adapter, I was getting sluggish behavior. When I tried the dummy, it was very responsive. So I'm hoping to just create another dummy. I'm using KDE DM. I have seen many examples of using VIRTUAL1 but I can't get that working with the dummy driver. I tried adding Option "VirtualHeads" "2" into the config but the dummy driver doesn't recognize it. I’ve seen suggestions of using Xvfb but it has been deprecated by the dummy driver since 2016. Here are some details.

$ uname -a
Linux bgrupczy-linux 5.8.0-53-generic #60~20.04.1-Ubuntu SMP Thu May 6 09:52:46 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

/usr/share/X11/xorg.conf.d/xorg.conf is empty The following was gleaned from searching the internet. Once I got it working I stopped tweaking it so it may have flaws but that don't seem to affect me. /usr/share/X11/xorg.conf.d/dummy-1920x1080.conf has the following which gets me my single 1920x1080.

Section "Monitor"
  Identifier "Monitor0"
  HorizSync 28.0-80.0
  VertRefresh 48.0-75.0
  Modeline "1920x1080_60.00" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync
EndSection

Section "Device"
  Identifier "Card0"
  Driver "dummy"
  VideoRam 256000
EndSection

Section "Screen"
  Identifier "Screen0"
  Device "Card0"
  Monitor "Monitor0"
  DefaultDepth 24
  SubSection "Display"
    Depth 24
    Modes "1920x1080_60.00"
  EndSubSection
EndSection

$ xrandr
xrandr: Failed to get size of gamma for output default
Screen 0: minimum 320 x 240, current 1920 x 1080, maximum 1920 x 1080
default connected 1920x1080+0+0 0mm x 0mm
   1920x1080     60.00* 
   1680x1050     70.00    60.00  
   1400x1050     70.00    60.00  
   1600x900      60.00  
   1280x1024     75.00    60.00  
   1440x900      60.00  
   1400x900      60.00  
   1280x960      60.00  
   1368x768      60.00  
   1360x768      60.00  
   1280x800      60.00  
   1152x864      75.00    70.00    60.00  
   1280x720      60.00  
   1024x768      75.00    70.00    60.00  
   1024x576      60.00  
   960x600       60.00  
   832x624       75.00  
   960x540       60.00  
   800x600       75.00    72.00    60.00    56.00  
   840x525       70.00    60.00  
   864x486       60.00  
   700x525       70.00    60.00  
   800x450       60.00  
   640x512       75.00    60.00  
   720x450       60.00  
   700x450       60.00  
   640x480       75.00    73.00    60.00  
   684x384       60.00  
   680x384       60.00  
   640x400       60.00  
   576x432       75.00    70.00    60.00  
   640x360       60.00  
   512x384       75.00    70.00    60.00  
   512x288       60.00  
   416x312       75.00  
   480x270       60.00  
   400x300       75.00    72.00    60.00    56.00  
   432x243       60.00  
   320x240       75.00    73.00    60.00

$ lspci | grep VGA
00:02.0 VGA compatible controller: Intel Corporation Device 9bc5 (rev 05)

I can see from xrandr that my monitor is called "default". So I tried this:

$ cvt 3840 1080
# 3840x1080 59.96 Hz (CVT) hsync: 67.16 kHz; pclk: 346.00 MHz
Modeline "3840x1080_60.00"  346.00  3840 4088 4496 5152  1080 1083 1093 1120 -hsync +vsync

$ xrandr --newmode "3840x1080_60.00"  346.00  3840 4088 4496 5152  1080 1083 1093 1120 -hsync +vsync
$ xrandr --addmode default "3840x1080_60.00"
$ xrandr --output default --mode "3840x1080_60.00"

The last line gives me:

xrandr: Configure crtc 0 failed

I tried to increase VideoRam to 512000 (double) to make sure I had room. Not sure what to do there. I have 32G ram. And ALL xrandr commands give me:

: Failed to get size of gamma for output default

and I figure that's because it's a dummy monitor that has no gamma. I'm currently Working within the VNC session. Do I need to shut down x11vnc to get xrandx to complete? I'm at my wits end. I'm starting x11vnc like this:

x11vnc -loop -forever -shared -repeat -noxdamage -xrandr -display :0 -clip 1920x1080+0+0

The linux box is within my local net so I'm not concerned with authentication/passwords. **Edit 2021-05-27:** More lurking and I found some options. I was able to get a double wide screen and then create two x11vnc instances. But this isn't optimal. The Linux box still sees this as a single screen. Now is there a way to take that screen and tell the Linux box to split it? For example, if I maximize a window in KDE it will not span both local screens? Xorg conf file:

Section "Monitor"
  Identifier "Monitor0"
EndSection

Section "Device"
  Identifier "Card0"
  Driver "dummy"
  VideoRam 512000
EndSection

Section "Screen"
  Identifier "Screen0"
  Device "Card0"
  Monitor "Monitor0"
  DefaultDepth 24
  SubSection "Display"
    Depth 24
    Virtual 3840 1080
  EndSubSection
EndSection

x11vnc -loop -forever -shared -repeat -noxdamage -xrandr -display :0 -rfbport 5900 -clip 1920x1080+0+0
x11vnc -loop -forever -shared -repeat -noxdamage -xrandr -display :0 -rfbport 5901 -clip 1920x1080+1920+0

I can then connect to VNC displays :0 and :1 and arrange them on local monitors and resize the windows to fit those monitors. When a dialog window appears, many times it's in the middle of the Linux "big screen" which for me spans both monitors... **Edit 2021-11-12:** One solution: https://superuser.com/a/1188573/514658 The real issue is not being able to get my VNC viewer to go full screen and only span two of my three monitors. The only option available in the viewer is to use ALL monitors which then blocks my use of the Windows side. DisplayFusion at above link did the trick. Now I can seamlessly drag between my two monitors and not get stuck on the edge of one. **Edit 2021-11-16:** "SOLVED": Instead of using DisplayFusion, which is a big hammer, more searching led me to Windows PowerShell. No need for a third party utility. I only need to move/resize a specific window to fit on two of my three monitors full screen. Here it is:

Add-Type @"
  using System;
  using System.Runtime.InteropServices;

  public class Win32 {
    [DllImport("user32.dll")]
    [return: MarshalAs(UnmanagedType.Bool)]
    public static extern bool GetWindowRect(IntPtr hWnd, out RECT lpRect);

    [DllImport("user32.dll")]
    [return: MarshalAs(UnmanagedType.Bool)]
    public static extern bool GetClientRect(IntPtr hWnd, out RECT lpRect);

    [DllImport("user32.dll")]
    [return: MarshalAs(UnmanagedType.Bool)]
    public static extern bool MoveWindow(IntPtr hWnd, int X, int Y, int nWidth, int nHeight, bool bRepaint);
  }

  public struct RECT
  {
    public int Left;        // x position of upper-left corner
    public int Top;         // y position of upper-left corner
    public int Right;       // x position of lower-right corner
    public int Bottom;      // y position of lower-right corner
  }

"@

$h = (Get-Process vnc-E4_6_3-x86_win32_viewer).MainWindowHandle

I am developing an application that uses x11vnc in the background and I would like to know how many users are currently connected. I have reviewed the list of commands but I have not found anything for that purpose. Any ideas?

I need to run Firefox (or some other web browser, but I prefer Firefox) on a non-local (i.e. not on my PC, not reachable via LAN) Unix virtual machine and then control it using keyboard and mouse, because some websites only work with Javascript and don't allow downloads unless I'm logged in.

-X

doesn't cut it, because it is a pain to use unless you are connected to the Internet with 10 Gbit/s. And I don't really feel like installing one of the fat "lightweight" desktop environments like Gnome or Xfce. And of course Firefox is not supposed to run as root.

I want to connect via VNC to my workstation. I have access to the box via SSH over a VPN. On my workstation I start my VNC server like this x11vnc -rfbport 5901 -rfbauth /home//.vnc/passwd -usepw -display :0 OS is a Cenots7. I'm only user and have no sudo or root privileges. My VNC client can connect to the server and I confirmed that keyboard and mouse events arrive at the server with -dp and -dk. However, the image I get of my workstation desktop is shifted down vertically by a few hundred pixel thus creating a black box at the top and the bottom is cut off. Additionally the workstation does not react to any input. I made sure the workstation has a monitor connected that is switched on. I'm searching for hours but can't find a clue on what's going on. Maybe I find help here.

So my team is building a few Autodesk Flame systems using Rocky Linux 9.3 that we would like to be able to access using VNC. We installed x11VNC but are only able to access it remotely if we start and enable the vnc app after it has turned on using a local monitor and keyboard, defeating the purpose. How do we configure the x11vnc.service in order to be able to access it with VNC without having to first go and start the app manually and locally? Would also like to be able to 'log off' the Rocky Linux 9.3 system and still see its login screen in order to switch users while connected through VNC remotely. Here is my x11vnc.service file: [Unit] Description=VNC server for the current X11 session After=display-manager.service [Service] ExecStart=/usr/bin/x11vnc -auth guess -cursor arrow -display :0 -forever -loop -noallinput -nobell -nodpms -noipv6 -nomodtweak -nopw -norc -nossl -noxdamage -noxfixes -noxkb -noxrecord -o /var/log/x11vnc.log -reopen -repeat -rfbauth /root/.vnc/x11vnc.passwd -rfbport 5900 -rfbversion 3.8 -shared Restart=on-failure RestartSec=3 [Install] WantedBy=graphical.target Thank you soo much for anybody who can help me solve this issue. Ill be forever in your debt.

I'm running a headless Linux Mint (19.3) server for Plex and Homebridge. I only manage it via SSH or VNC. Currently running x11vnc (0.9.13) with the following config -noxrecord -ncachecr -auth guess -forever -noxdamage -repeat -rfbauth /etc/x11vnc/vncpwd -rfbport -shared Everything works fine except input lag on VNC is nearly unbearable. Typing is about a character every 2 seconds and mouse movement/clicks are also very slow. When the screen changes e.g. showing some sort of animation, it seems to be at a near normal pace that I'd expect for VNC. Also when I SSH to the machine, everything is perfectly speedy.

Running Xubuntu 20.04 as VM on top of Ubuntu Server 20.04 with bridged interface. I am able to connect to the VM via SSH (also using Putty on Windows 10 machine that will access the VM). Using VNCViewer (part of the TigerVNC project) on a Windows 10 machine I entered the IP address of the VM. A popup for password is displayed where I enter the password but when I click connect I get TigerVNC An unexpected error occurred when communicating with the server: Authentication failure: password check failed! Attempt to reconnect? [No] [Yes] I installed x11vnc the usual way using apt. Following instructions online I created * an encrypted password file sudo x11vnc -storepasswd PASSWORD /home/USER/.vnc/passwd * an unencrypted password file echo PASSWORD > /home/USER/.vnc/password Respectively I executed x11vnc -forever -shared -display :0 -rfbauth /home/user/.vnc/passwd for the encrypted and x11vnc -forever -shared -display :0 -passwdfile /home/xubuntu/.vnc/passwd for the unencrypted password file. **Note:** Obviously I didn't do both in parallel. Also password typo is impossible due to the simplicity of the password (something like "abcd"). Both yielded the following log in the SSH terminal: x11vnc -forever -shared -display :0 -passwdfile /home/xubuntu/.vnc/passwd 30/03/2022 10:38:02 x11vnc version: 0.9.16 lastmod: 2019-01-05 pid: 6641 30/03/2022 10:38:02 Using X display :0 30/03/2022 10:38:02 rootwin: 0x53b reswin: 0x3800001 dpy: 0xc07a6840 30/03/2022 10:38:02 30/03/2022 10:38:02 ------------------ USEFUL INFORMATION ------------------ 30/03/2022 10:38:02 X DAMAGE available on display, using it for polling hints. 30/03/2022 10:38:02 To disable this behavior use: '-noxdamage' 30/03/2022 10:38:02 30/03/2022 10:38:02 Most compositing window managers like 'compiz' or 'beryl' 30/03/2022 10:38:02 cause X DAMAGE to fail, and so you may not see any screen 30/03/2022 10:38:02 updates via VNC. Either disable 'compiz' (recommended) or 30/03/2022 10:38:02 supply the x11vnc '-noxdamage' command line option. 30/03/2022 10:38:02 30/03/2022 10:38:02 Wireframing: -wireframe mode is in effect for window moves. 30/03/2022 10:38:02 If this yields undesired behavior (poor response, painting 30/03/2022 10:38:02 errors, etc) it may be disabled: 30/03/2022 10:38:02 - use '-nowf' to disable wireframing completely. 30/03/2022 10:38:02 - use '-nowcr' to disable the Copy Rectangle after the 30/03/2022 10:38:02 moved window is released in the new position. 30/03/2022 10:38:02 Also see the -help entry for tuning parameters. 30/03/2022 10:38:02 You can press 3 Alt_L's (Left "Alt" key) in a row to 30/03/2022 10:38:02 repaint the screen, also see the -fixscreen option for 30/03/2022 10:38:02 periodic repaints. 30/03/2022 10:38:02 30/03/2022 10:38:02 XFIXES available on display, resetting cursor mode 30/03/2022 10:38:02 to: '-cursor most'. 30/03/2022 10:38:02 to disable this behavior use: '-cursor arrow' 30/03/2022 10:38:02 or '-noxfixes'. 30/03/2022 10:38:02 using XFIXES for cursor drawing. 30/03/2022 10:38:02 GrabServer control via XTEST. 30/03/2022 10:38:02 30/03/2022 10:38:02 Scroll Detection: -scrollcopyrect mode is in effect to 30/03/2022 10:38:02 use RECORD extension to try to detect scrolling windows 30/03/2022 10:38:02 (induced by either user keystroke or mouse input). 30/03/2022 10:38:02 If this yields undesired behavior (poor response, painting 30/03/2022 10:38:02 errors, etc) it may be disabled via: '-noscr' 30/03/2022 10:38:02 Also see the -help entry for tuning parameters. 30/03/2022 10:38:02 You can press 3 Alt_L's (Left "Alt" key) in a row to 30/03/2022 10:38:02 repaint the screen, also see the -fixscreen option for 30/03/2022 10:38:02 periodic repaints. 30/03/2022 10:38:02 30/03/2022 10:38:02 XKEYBOARD: number of keysyms per keycode 7 is greater 30/03/2022 10:38:02 than 4 and 51 keysyms are mapped above 4. 30/03/2022 10:38:02 Automatically switching to -xkb mode. 30/03/2022 10:38:02 If this makes the key mapping worse you can 30/03/2022 10:38:02 disable it with the "-noxkb" option. 30/03/2022 10:38:02 Also, remember "-remap DEAD" for accenting characters. 30/03/2022 10:38:02 30/03/2022 10:38:02 X FBPM extension not supported. Xlib: extension "DPMS" missing on display ":0". 30/03/2022 10:38:02 X display is not capable of DPMS. 30/03/2022 10:38:02 -------------------------------------------------------- 30/03/2022 10:38:02 30/03/2022 10:38:02 Default visual ID: 0x21 30/03/2022 10:38:02 Read initial data from X display into framebuffer. 30/03/2022 10:38:02 initialize_screen: fb_depth/fb_bpp/fb_Bpl 24/32/4096 30/03/2022 10:38:02 30/03/2022 10:38:02 X display :0 is 32bpp depth=24 true color 30/03/2022 10:38:02 30/03/2022 10:38:02 Autoprobing TCP port 30/03/2022 10:38:02 Autoprobing selected TCP port 5901 30/03/2022 10:38:02 Autoprobing TCP6 port 30/03/2022 10:38:02 rfbListenOnTCP6Port: error in bind IPv6 socket: Address already in use 30/03/2022 10:38:02 Autoprobing selected TCP6 port 5901 30/03/2022 10:38:02 listen6: bind: Address already in use 30/03/2022 10:38:02 Not listening on IPv6 interface. 30/03/2022 10:38:02 30/03/2022 10:38:02 Xinerama is present and active (e.g. multi-head). 30/03/2022 10:38:02 Xinerama: number of sub-screens: 1 30/03/2022 10:38:02 Xinerama: no blackouts needed (only one sub-screen) 30/03/2022 10:38:02 30/03/2022 10:38:02 fb read rate: 230 MB/sec 30/03/2022 10:38:02 fast read: reset -wait ms to: 10 30/03/2022 10:38:02 fast read: reset -defer ms to: 10 30/03/2022 10:38:02 The X server says there are 10 mouse buttons. 30/03/2022 10:38:02 screen setup finished. 30/03/2022 10:38:02 The VNC desktop is: SZA-DT043-L-VM0:1 PORT=5901 ****************************************************************************** Have you tried the x11vnc '-ncache' VNC client-side pixel caching feature yet? The scheme stores pixel data offscreen on the VNC viewer side for faster retrieval. It should work with any VNC viewer. Try it by running: x11vnc -ncache 10 ... One can also add -ncache_cr for smooth 'copyrect' window motion. More info: http://www.karlrunge.com/x11vnc/faq.html#faq-client-caching One thing I noticed is that at least in the case of creating an unencrypted password file running x11vnc with sudo yields an error 30/03/2022 10:46:06 x11vnc version: 0.9.16 lastmod: 2019-01-05 pid: 6708 No protocol specified 30/03/2022 10:46:06 XOpenDisplay(":0") failed. 30/03/2022 10:46:06 Trying again with XAUTHLOCALHOSTNAME=localhost ... No protocol specified 30/03/2022 10:46:06 *************************************** 30/03/2022 10:46:06 *** XOpenDisplay failed (:0) ***x11vnc was unable to open the X DISPLAY ":0", it cannot continue ***There may be "Xlib:" error message above with details about the failure Some tips and guidelines ... I don't know how this affects the problem I am having but thought it might provide some insight to the more knowledgeable folks around here. Since it's an internal company network I am not worried about someone breaking into my VM (which is meant to be disposable anyway). I will try to setup X11VNC without any authentication (if possible) but even if that works I am still interested into the cause of the issue at hand.

I have x11vnc running inside a docker container with alpine as base image. (5900 is exposed and mapped to hosts 5900) I use Xvfb as well. I run x11vnc inside the container using this command x11vnc -display :0 -forever -nopw -listen 0.0.0.0 -xkb I can connect to ths normally using a normal vnc client like realvnc without any issue and any unusual delay. This is the output when real vnc is used 24/09/2024 15:42:00 Got connection from client 112.134.157.141 24/09/2024 15:42:00 0 other clients 24/09/2024 15:42:00 Normal socket connection 24/09/2024 15:42:00 Disabled X server key autorepeat. 24/09/2024 15:42:00 to force back on run: 'xset r on' (3 times) 24/09/2024 15:42:00 incr accepted_client=2 for 112.134.157.141:48624 sock=10 24/09/2024 15:42:01 Client Protocol Version 3.8 24/09/2024 15:42:01 Protocol version sent 3.8, using 3.8 24/09/2024 15:42:01 rfbProcessClientSecurityType: executing handler for type 1 24/09/2024 15:42:01 rfbProcessClientSecurityType: returning securityResult for client rfb version >= 3.8 24/09/2024 15:42:01 created xdamage object: 0xc00026 24/09/2024 15:42:03 client_set_net: 112.134.157.141 0.0016 24/09/2024 15:42:03 rfbProcessClientNormalMessage: ignoring unsupported encoding type Enc(0x00000018) 24/09/2024 15:42:03 rfbProcessClientNormalMessage: ignoring unsupported encoding type Enc(0x00000016) 24/09/2024 15:42:03 rfbProcessClientNormalMessage: ignoring unsupported encoding type Enc(0x00000015) 24/09/2024 15:42:03 rfbProcessClientNormalMessage: ignoring unsupported encoding type Enc(0x0000000F) 24/09/2024 15:42:03 rfbProcessClientNormalMessage: ignoring unsupported encoding type Enc(0xFFFFFEC6) 24/09/2024 15:42:03 Enabling full-color cursor updates for client 112.134.157.141 24/09/2024 15:42:03 Enabling NewFBSize protocol extension for client 112.134.157.141 24/09/2024 15:42:03 Using ZRLE encoding for client 112.134.157.141 24/09/2024 15:42:03 Pixel format for client 112.134.157.141: 24/09/2024 15:42:03 8 bpp, depth 6 24/09/2024 15:42:03 true colour: max r 3 g 3 b 3, shift r 4 g 2 b ' But when i try to connect it through react-vnc (which uses noVNC) It takes a long time to connect This is the output from x11vnc when attempting to connect with react-vnc, it get stuck at "created xdamage object: 0xc00027" for about 4 mins. 24/09/2024 15:42:43 Got connection from client 112.134.157.141 24/09/2024 15:42:43 0 other clients 24/09/2024 15:42:43 Got 'ws' WebSockets handshake 24/09/2024 15:42:43 - webSocketsHandshake: using binary/raw encoding 24/09/2024 15:42:43 - WebSockets client version hybi-13 24/09/2024 15:42:43 Disabled X server key autorepeat. 24/09/2024 15:42:43 to force back on run: 'xset r on' (3 times) 24/09/2024 15:42:43 incr accepted_client=3 for 112.134.157.141:47494 sock=10 24/09/2024 15:42:43 created xdamage object: 0xc00027 24/09/2024 15:46:42 hybiReadHeader: read; Connection reset by peer 24/09/2024 15:46:42 rfbProcessClientProtocolVersion: read: Connection reset by peer 24/09/2024 15:46:42 client_count: 0 24/09/2024 15:46:42 Restored X server key autorepeat to: 1 24/09/2024 15:46:42 Client 112.134.157.141 gone 24/09/2024 15:46:42 Statistics events Transmit/ RawEquiv ( saved) 24/09/2024 15:46:42 TOTALS : 0 | 0/ 0 ( 0.0%) 24/09/2024 15:46:42 Statistics events Received/ RawEquiv ( saved) 24/09/2024 15:46:42 TOTALS : 0 | 0/ 0 ( 0.0%) 24/09/2024 15:46:45 destroyed xdamage object: 0xc00027 ' it get stuck at "**created xdamage object: 0xc00027**" for about **4 mins**. And starts working after "**connection reset by peer**" This is what the next.js implementation looks like. "use client"; import React, { useRef } from 'react'; import { VncScreen } from 'react-vnc'; function App() { const ref = useRef(); return ( :5900/' scaleViewport background="#000000" style={{ width: '100vw', height: '100vh', }} ref={ref} /> ); } export default App; in chrome i also get this warning "index.es.js:9621 WebSocket connection to 'ws://:5900/' failed: WebSocket is closed before the connection is established. close @ index.es.js:9621 " Is this normal, if not how to fix

Can guacamole change the viewport to a single monitor on a multimonitor system? Is this a feature VNC clients possess in general? I have VNC server running on a multimonitor system, ie a laptop with its built-in 1366x768 screen and a 1920x1080 monitor. When I check the VNC server logs it indicates it shows that a 3286x1080 virtual screen has been created. Regardless of how I set the geometry to be 3286x1080+1366+0, or leave it to the defaults this is what guacamole displays. I have tried x11vnc -geometry 3286x1080+1366+0 -noxdamage -ncache_cr -wait 5 -defer 5 -display :5 and x11vnc -noxdamage -ncache_cr -wait 5 -defer 5 -display :5 I didn't fare much better with x0tigervncserver either. This part of the log when x11vnc starts up. 29/08/2024 13:40:11 29/08/2024 13:40:11 X FBPM extension not supported. 29/08/2024 13:40:11 X display is capable of DPMS. 29/08/2024 13:40:11 -------------------------------------------------------- 29/08/2024 13:40:11 29/08/2024 13:40:11 Default visual ID: 0x21 29/08/2024 13:40:11 Read initial data from X display into framebuffer. 29/08/2024 13:40:11 initialize_screen: fb_depth/fb_bpp/fb_Bpl 24/32/13144 29/08/2024 13:40:11 WARNING: Width (3286) is not a multiple of 4. VncViewer has problems with that. 29/08/2024 13:40:11 29/08/2024 13:40:11 X display :5 is 32bpp depth=24 true color 29/08/2024 13:40:11 29/08/2024 13:40:11 Autoprobing TCP port 29/08/2024 13:40:11 Autoprobing selected TCP port 5900 29/08/2024 13:40:11 Autoprobing TCP6 port 29/08/2024 13:40:11 Autoprobing selected TCP6 port 5900 29/08/2024 13:40:11 listen6: bind: Address already in use 29/08/2024 13:40:11 Not listening on IPv6 interface. 29/08/2024 13:40:11 29/08/2024 13:40:11 Xinerama is present and active (e.g. multi-head). 29/08/2024 13:40:11 Xinerama: number of sub-screens: 2 29/08/2024 13:40:11 Xinerama: enabling -xwarppointer mode to try to correct 29/08/2024 13:40:11 Xinerama: mouse pointer motion. XTEST+XINERAMA bug. 29/08/2024 13:40:11 Xinerama: Use -noxwarppointer to force XTEST. 29/08/2024 13:40:11 Xinerama: sub-screen 1366x768+0+0 29/08/2024 13:40:11 Xinerama: sub-screen 1920x1080+1366+0 29/08/2024 13:40:11 blackout rect: 1366x312+0+768: x=0-1366 y=768-1080 29/08/2024 13:40:11 29/08/2024 13:40:11 fb read rate: 1678 MB/sec 29/08/2024 13:40:11 The X server says there are 10 mouse buttons. 29/08/2024 13:40:11 screen setup finished. 29/08/2024 13:40:11 29/08/2024 13:40:11 WARNING: You are running x11vnc WITHOUT a password. See 29/08/2024 13:40:11 WARNING: the warning message printed above for more info. 29/08/2024 13:40:11 Can guacamole be made to pan the necessary part of the virtual screens and apply the scaling to that portion only? When I use krdc I'm able to scroll the windows to the necessary part of the screen and the screen is normalized. When I use a laptop screen with 1920x1080 screen which matches the monitor, using the option -geometry 3840x1080+1920+0 the display works fine as expected.

I want to connect to my office PC from my home PC via VNC. I ssh'd to my office PC with ssh keys and start a server: "vncserver :2 -SecurityTypes=none". Then logout and start the viewer on my home PC: "vncviewer -via 'jump host' 'server PC' :2". The viewer opens a window and tells me that I'm connected. But..... The screen is black!! Only the very first time it worked. Now nothing happens, the screen stays black. Is this a DISPLAY error? Or what do you guess. I read a lot about this problem, but nothing seems to help. --- I killed the vncserver manually and/or deleted the /tmp/.X0 or any other file of the same kind. Using "ps aux | grep vnc" shows nothing. Surprisingly, after I deleted the vnc program, I got using "echo $DISPLAY" the answer: "localhost:10.0". Why? I think the normal display number is 0. --- I want to add some new observations. I CAN start the VNC viewer if I only use the twm displaymanager in the .xstartup file on the server site. If I use startkde instead it gives me a "Call to lnusertemp failed (temporary directories full?). Check your installation." and the screen is black. I checked /var/tmp and /tmp, but there is enough space . What to do?. How do I know if Wayland is running or not?

I am running an Xfce desktop environment in Docker from [here](https://github.com/ConSol/docker-headless-vnc-container) and connected to it using a VNC client and a browser (backed by noVNC) but in both cases the output doesn't fill the screen - or at least the dimensions of the output don't change so that when the output hits the edge of my local screen there are gaps. Is there a way I can get the output to fill my local screen by dynamically adjusting the dimensions/resolution? Or would I need to work out my local dimensions manually first and reload X/VNC? (quite new to how GUIs work in Linux work so not too sure if this is something that'd be configured in VNC server or in X server)

I'd like to set up VNC server on a Debian machine to run as a service so I can turn on a remote machine and access it without the need to be physically present. One option is to set it up in the user-bus:

$ systemctl --user cat vnc.service
# /home/stew/.config/systemd/user/vnc.service
[Unit]
Description=VNC Server
After=default.target

[Service]
ExecStart=x11vnc -nevershared -forever -nopw

[Install]
WantedBy=default.target

This works, but still requires the me to physically sit at the terminal to log into gdm3 to get XAUTHORITY before I can do any remote work. If I ssh in before logging in with gdm3, the service fails. I work around this by using AutomaticLoginEnable=True and AutomaticLogin=stew in /etc/gdm3/daemon.conf. Instead, I'd like to be able to use VNC without the need to log in as a specific user first (similar to RDP). I think the best way to do this is to use -nopw to get to a gdm3 screen. I tried to do that with:

$ systemctl cat vnc.service
# /etc/systemd/system/vnc.service
[Unit]
Description=VNC Service (system-wide)
After=graphical.target

[Service]
ExecStart=x11vnc -auth /run/user/116/gdm/Xauthority -display :0 -nopw

[Install]
WantedBy=graphical.target

I found the XAUTHORITY path with this command which revealed the path is owned by UID 116 (system user: Debian-gdm).

stew ~ $ ps wwwwaux | grep auth
root        1033  0.1  0.5 189548 63596 tty1     Sl+  14:32   0:00 /usr/lib/xorg/Xorg vt1 -displayfd 3 -auth /run/user/116/gdm/Xauthority -nolisten tcp -background none -noreset -keeptty -novtswitch -verbose 3

I also need to set WaylandEnable=false in /etc/gdm3/daemon.conf because VNC doesn't seem to work with Wayland. At first, this seems to work well. I get the gdm login screen. But, when I try to log in as a user, the auth gets transferred to another user and I am disconnected. Is there a way to set up VNC so I can log in via gdm?

as far as i can tell, everything is configured correctly. the service file is as follows:

[Unit]
Description=Start x11vnc at startup
After=multi-user.target

[Service]
Type=simple
ExecStart=/usr/bin/x11vnc -auth guess -display :0 -forever -loop -noxdamage -repeat -rfbauth /etc/x11nvc.pass -rfbport 5900 -shared
ExecStop=/usr/bin/killall x11vnc
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target

the password is stored in /etc/x11vnc.pass using sudo x11vnc -storepasswd /etc/x11vnc.pass. i have reloaded the daemon: sudo systemctl daemon-reload and enabled the service: sudo systemctl enable x11vnc, and started the service sudo systemctl start x11vnc. on reboot, the service comes up just fine, but when i attempt to access it with VNC Viewer, after entering the correct password, i simply get a password check failed error: here's the kink: when i go to the machine itself and open the x11vnc utility, once i check the Allow Connections button, everything works just fine. problem is, this is an unattended kiosk panel and we can't be doing that everytime it restarts... because it's on the other side of the country. system is Debian 10.13 Buster and there is no firewall running yet. can someone kindly point out what i am missing?

am trying to open sdl gui based program in freebsd system from remote connection via x11vnc. there is no display connected to the pc therefor i used a dummy driver. keep getting this error > libGL error: MESA-LOADER: failed to open swrast: Cannot open "/usr/local/lib/dri-devel/swrast_dri.so" (search paths /usr/local/lib/dri-devel, suffix _dri) libGL error: failed to load driver: swrast X Error of failed request: BadValue (integer parameter out of range for operation) Major opcode of failed request: 150 (GLX) Minor opcode of failed request: 3 (X_GLXCreateContext) Value in failed request: 0x0 Serial number of failed request: 234 Current serial number in output stream: 235 i tired to set SDL_VIDEODRIVER=dummy but then the program works without seeing any trace of the sdl app GUI

a newbie here. I just installed kitty on wsl kali-linux, I am using win-kex to use a GUI. When I launch kitty opens on another window "outside" the winkex instance: like a Windows app. So, how can I make kitty work "inside" the winkex session? The message after call kitty is: > ignoreboth or ignorespace present in bash HISTCONTROL setting, showing > running command in window title will not be robust

I'm trying to get my Ubuntu box to run at a higher resolution than the default 1024x768. As you can see from the log, i'm using integrated Intel video drivers. I've tried adding an xorg.conf with a dummy monitor but I still get the default resolution. I've also tried specifying the geometry in the x11vnc.service. Then I added a custom dummy monitor config, as below. /usr/share/X11/xorg.conf.d/10-monitor.conf Section "Monitor" Identifier "Monitor0" Option "Enable" "true" Option "DPMS" "false" DisplaySize 400 300 EndSection Section "Device" Identifier "Device0" Driver "intel" EndSection Section "Screen" Identifier "Screen0" Device "Device0" Monitor "Monitor0" DefaultDepth 24 SubSection "Display" Depth 24 Modes "1920x1080" "1600x1200" "1280x768" EndSubSection EndSection File: /var/log/Xorg.0.log [ 3.564] (II) Module glx: vendor="X.Org Foundation" [ 3.564] compiled for 1.18.4, module version = 1.0.0 [ 3.564] ABI class: X.Org Server Extension, version 9.0 [ 3.564] (==) AIGLX enabled [ 3.564] (II) LoadModule: "intel" [ 3.565] (II) Loading /usr/lib/xorg/modules/drivers/intel_drv.so [ 3.567] (II) Module intel: vendor="X.Org Foundation" [ 3.567] compiled for 1.18.4, module version = 2.99.917 [ 3.567] Module class: X.Org Video Driver [ 3.567] ABI class: X.Org Video Driver, version 20.0 [ 3.567] (II) intel: Driver for Intel(R) Integrated Graphics Chipsets: i810, i810-dc100, i810e, i815, i830M, 845G, 854, 852GM/855GM, 865G, 915G, E7221 (i915), 915GM, 945G, 945GM, 945GME, Pineview GM, Pineview G, 965G, G35, 965Q, 946GZ, 965GM, 965GME/GLE, G33, Q35, Q33, GM45, 4 Series, G45/G43, Q45/Q43, G41, B43 [ 3.567] (II) intel: Driver for Intel(R) HD Graphics: 2000-6000 [ 3.567] (II) intel: Driver for Intel(R) Iris(TM) Graphics: 5100, 6100 [ 3.567] (II) intel: Driver for Intel(R) Iris(TM) Pro Graphics: 5200, 6200, P6300 [ 3.570] (II) intel(0): Using Kernel Mode Setting driver: i915_bpo, version 1.6.0 20160425 [ 3.570] (II) intel(0): SNA compiled: xserver-xorg-video-intel 2:2.99.917+git20160325-1ubuntu1.2 (Timo Aaltonen ) [ 3.570] (II) intel(0): SNA compiled for use with valgrind [ 3.571] (--) intel(0): gen9 engineering sample [ 3.571] (--) intel(0): CPU: x86-64, sse2, sse3, ssse3, sse4.1, sse4.2; using a maximum of 2 threads [ 3.571] (**) intel(0): Depth 24, (--) framebuffer bpp 32 [ 3.571] (==) intel(0): RGB weight 888 [ 3.571] (==) intel(0): Default visual is TrueColor [ 3.572] (II) intel(0): Output HDMI1 using monitor section Monitor0 [ 3.572] (**) intel(0): Option "Enable" "true" [ 3.572] (II) intel(0): Enabled output HDMI1 [ 3.572] (II) intel(0): Output HDMI2 has no monitor section [ 3.572] (II) intel(0): Enabled output HDMI2 [ 3.572] (II) intel(0): Output DP1 has no monitor section [ 3.572] (II) intel(0): Enabled output DP1 [ 3.572] (--) intel(0): Using a maximum size of 256x256 for hardware cursors [ 3.572] (II) intel(0): Output VIRTUAL1 has no monitor section [ 3.572] (II) intel(0): Enabled output VIRTUAL1 [ 3.572] (==) intel(0): TearFree disabled [ 3.572] (**) intel(0): Display dimensions: (400, 300) mm [ 3.572] (**) intel(0): DPI set to (65, 65) [ 3.572] (II) Loading sub module "dri2" [ 3.572] (II) LoadModule: "dri2" [ 3.572] (II) Module "dri2" already built-in [ 3.572] (II) Loading sub module "present" [ 3.572] (II) LoadModule: "present" [ 3.572] (II) Module "present" already built-in [ 3.572] (==) Depth 24 pixmap format is 32 bpp [ 3.575] (II) intel(0): SNA initialized with Kabylake (gen9) backend [ 3.575] (==) intel(0): Backing store enabled [ 3.575] (==) intel(0): Silken mouse enabled [ 3.575] (II) intel(0): HW Cursor enabled [ 3.575] (II) intel(0): RandR 1.2 enabled, ignore the following RandR disabled message. [ 3.576] (==) intel(0): Display hotplug detection enabled [ 3.576] (II) intel(0): [DRI2] Setup complete [ 3.576] (II) intel(0): [DRI2] DRI driver: i965 ^G Get Help ^O Write Out ^W Where Is ^K Cut Text ^J Justify ^C Cur Pos ^Y Prev Page M-\ First Line M-W WhereIs Next ^^ Mark Text M-} Indent Text M-U Undo ^B Back ^X Exit ^R Read File ^\ Replace ^U Uncut Text ^T To Spell ^_ Go To Line ^V Next Page M-/ Last Line M-] To Bracket M-^ Copy Text M-{ Unindent Text M-E Redo ^F Forwards /lib/systemd/system/x11vnc.service: [Unit] Description="x11vnc" Requires=display-manager.service After=display-manager.service [Service] ExecStart=/usr/bin/x11vnc -xkb -norc -forever -shared -display :0 -xrandr -auth guess -rfbauth /etc/x11vnc.pass -localhost -o /var/log/x11vnc.log ExecStop=/usr/bin/killall x11vnc Restart=on-failure Restart-sec=2 [Install] WantedBy=multi-user.target