Install x11

The LifeKeeper for the Linux GUI uses the X Window System. We need to install it on each node.

• Install x11 to the machine.

• Install x11 related packages and enable it with the following steps:

1. Install x11 related packages.

# yum install  xorg-x11-server-Xorg xorg-x11-xauth -y
Last metadata expiration check: 0:00:51 ago on Wed 18 Nov 2020 12:36:11 AM UTC.
Dependencies resolved.
==================================================================================================================
 Package                         Architecture    Version                    Repository                           Size
==================================================================================================================
Installing:
 xorg-x11-server-Xorg            x86_64          1.20.8-6.el8               rhel-8-appstream-rhui-rpms          1.5 M
 xorg-x11-xauth                  x86_64          1:1.0.9-12.el8             rhel-8-appstream-rhui-rpms           39 k
(snip)
  xorg-x11-drv-libinput-0.29.0-1.el8.x86_64                 xorg-x11-drv-vesa-2.4.0-3.el8.x86_64                      
  xorg-x11-server-Xorg-1.20.8-6.el8.x86_64                  xorg-x11-server-common-1.20.8-6.el8.x86_64                
  xorg-x11-xauth-1:1.0.9-12.el8.x86_64                      xorg-x11-xkb-utils-7.7-28.el8.x86_64                      
Complete! 

2. Check the X11Forwarding parameter in /etc/ssh/sshd_config to confirm that it is set to yes. If it is not set to yes, edit the file.

# cat /etc/ssh/sshd_config
(break)
#AllowAgentForwarding yes
#AllowTcpForwarding yes
#GatewayPorts no
X11Forwarding yes
#X11DisplayOffset 10
#X11UseLocalhost yes
#PermitTTY yes
(break)

3. Restart the machine.

# shutdown -r now 

Steps to Check Xauth list and Add the Xauth Entry

*These steps are only necessary if the user is not logged on as “root” using the su – command.

1. As the logon user on the system, get the DISPLAY environment variable value, using “echo $DISPLAY”.

2. Still as the logon user on the system, run “xauth list” and note the entry corresponding to the DISPLAY environment variable. (i.e. if the DISPLAY variable is “localhost:10.0”, then use the line starting with something like “host/unix:10”, but if it was “localhost:11.0”, then use the line starting with something like “host/unix:11”)

3. Switch to the root user.

4. Copy the entire line and run “xauth add <copied line>”.

5. Check that the DISPLAY environment variable as root is set the same as with the logon user, using the same method. If it is not, run “export DISPLAY=<logon user DISPLAY value>”.