How to start failed VNC service

Solution

The VNC server is configured on a Linux machine, but the service status is shown as failed.

systemctl status vncserver@:1.service
● vncserver@:1.service - Remote desktop service (VNC)
Loaded: loaded (/etc/systemd/system/vncserver@:1.service; enabled; vendor preset: disabled)
Active: failed (Result: exit-code) since Mon 2021-09-01 11:30:03 +04; 11s ago
Process: 13739 ExecStart=/usr/sbin/runuser -l vncuser -c /usr/bin/vncserver %i (code=exited, status=1/FAILURE)
Process: 13739 ExecStartPre=/bin/sh -c /usr/bin/vncserver -kill %i > /dev/null 2>&1 || : (code=exited, status=0/SUCCESS)
Main PID: 1231 (code=exited, status=0/SUCCESS)

The main reason for failed VNC server service is that X1-lock and socket files are present in /tmp/.X11-unix. Remove the files to start the VNC session.

rm /tmp/.X11-unix/X1 /tmp/.X1-lock

Start the VNC server service as follows:

systemctl start vncserver@:<display>.service

The root cause of this error is that files in /tmp/.X* are VNC session log files, and deliberately killing the session will not remove the /tmp/.X* files. The result is that the user cannot start the VNC session on the same display again. The first solution is to remove these stale files.

You should remove all stale files under these directories.

/tmp/.X11-unix/
X2 X3 X3 X5

/tmp/.X1-lock
.X0-lock .X11-unix/ .X1-lock .X2-lock .X3-lock .X4-lock