VNC not working with CentOS7

BhushanPathak · 06-05-2017, 01:45 AM

Hello,

I have a CentOS 7 minimal installation, on which I wish to install GNOME desktop & start a VNC session.

I followed this post to install GNOME desktop & start a VNC session.

When I try to connect to the machine using vnc viewer, it always times out & gives an error message -

Code:

Timed out waiting for response from the remote computer

Any idea how do I proceed further?

Thanks
Bhushan Pathak

hydrurga · 06-05-2017, 02:20 AM

Perhaps you have selinux or iptables enabled on either/both the source and destination systems, and that is interfering with the connection?

BhushanPathak · 06-08-2017, 02:01 AM

I have updated the firewalld service to open the ports for VNC service. Still the issue persists. Is there any log which I can check for errors?

tshikose · 06-08-2017, 06:00 AM

Hi,

I had similar problem with a Fedora 25 instance.
I put SE Linux in permissive mode to get VNC access.
I will later investigate why SE Linus is interfering with it.

Do

Code:

 setenforce 0

and try again.

BhushanPathak · 06-09-2017, 01:34 AM

Stopped the firewall & disabled selinux, still the issue persists

Code:

[hadoop@master ~]$ getenforce
Disabled
[hadoop@master ~]$ ps -ef | grep vnc
hadoop    1984     1  0 12:00 ?        00:00:00 /usr/bin/Xvnc :4 -desktop master.hadoopcluster.com:4 (hadoop) -auth /home/hadoop/.Xauthority -geometry 1024x768 -rfbwait 30000 -rfbauth /home/hadoop/.vnc/passwd -rfbport 5904 -fp catalogue:/etc/X11/fontpath.d -pn
hadoop    2383     1  0 12:00 ?        00:00:00 /usr/bin/vncconfig -iconic
hadoop    3172  2723  0 12:01 pts/0    00:00:00 grep --color=auto vnc
[hadoop@master ~]$ sudo /bin/systemctl stop firewalld
[hadoop@master ~]$ sudo /bin/systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled; vendor preset: enabled)
   Active: inactive (dead) since Fri 2017-06-09 12:02:01 IST; 7s ago
     Docs: man:firewalld(1)
  Process: 621 ExecStart=/usr/sbin/firewalld --nofork --nopid $FIREWALLD_ARGS (code=exited, status=0/SUCCESS)
 Main PID: 621 (code=exited, status=0/SUCCESS)

Jun 09 12:00:45 master.hadoopcluster.com systemd[1]: Starting firewalld - dynamic firewall daemon...
Jun 09 12:00:47 master.hadoopcluster.com systemd[1]: Started firewalld - dynamic firewall daemon.
Jun 09 12:02:00 master.hadoopcluster.com systemd[1]: Stopping firewalld - dynamic firewall daemon...
Jun 09 12:02:01 master.hadoopcluster.com systemd[1]: Stopped firewalld - dynamic firewall daemon.
[hadoop@master ~]$ sudo systemctl start vncserver@:4.service
[hadoop@master ~]$ sudo systemctl status vncserver@:4.service
● vncserver@:4.service - Remote desktop service (VNC)
   Loaded: loaded (/etc/systemd/system/vncserver@:4.service; enabled; vendor preset: disabled)
   Active: active (running) since Fri 2017-06-09 12:00:58 IST; 1min 23s ago
  Process: 1239 ExecStart=/usr/sbin/runuser -l hadoop -c /usr/bin/vncserver %i (code=exited, status=0/SUCCESS)
  Process: 1042 ExecStartPre=/bin/sh -c /usr/bin/vncserver -kill %i > /dev/null 2>&1 || : (code=exited, status=0/SUCCESS)
 Main PID: 1984 (Xvnc)
   CGroup: /system.slice/system-vncserver.slice/vncserver@:4.service
           ‣ 1984 /usr/bin/Xvnc :4 -desktop master.hadoopcluster.com:4 (hadoop) -auth /home/hadoop/.Xauthority -geometry 1024x768 -rfbwait 3...

Jun 09 12:00:54 master.hadoopcluster.com systemd[1]: Starting Remote desktop service (VNC)...
Jun 09 12:00:58 master.hadoopcluster.com systemd[1]: Started Remote desktop service (VNC).

BhushanPathak · 06-09-2017, 01:38 AM

The vnc server service file[/etc/systemd/system/vncserver@:4.service] config is -

Code:

[Unit]
Description=Remote desktop service (VNC)
After=syslog.target network.target

[Service]
Type=forking
# Clean any existing files in /tmp/.X11-unix environment
ExecStartPre=/bin/sh -c '/usr/bin/vncserver -kill %i > /dev/null 2>&1 || :'
ExecStart=/usr/sbin/runuser -l hadoop -c "/usr/bin/vncserver %i"
PIDFile=/home/hadoop/.vnc/%H%i.pid
ExecStop=/bin/sh -c '/usr/bin/vncserver -kill %i > /dev/null 2>&1 || :'

[Install]
WantedBy=multi-user.target

Anything I need to change?