Install and configure the X Windows Virtual Frame Buffer (Xvfb) (new installation)

You install X Windows Virtual Frame Buffer (Xvfb) to enable graphs in Oracle Empirica Signal.

Prerequisites:

Yum is installed and configured to use the appropriate configuration file.
Your system can connect to the yum repositories.

Note:

If Xvfb version 17.4-17.0.1.el6_9.1.x86_64 is installed or retrieved by yum, then either downgrade to 1.17.4-16.0.1.el6_9.1.x86_64, or obtain Xvfb version 1.17.4-17.0.2.el6 or later.

Perform these steps using the privileged user account on the application server.

Determine whether Xvfb is installed:
1. Execute the following command in a command shell:
  
  $ which Xvfb
  
  If a path to Xvfb appears, Xvfb is already installed. Alternatively, Xvfb is not installed.
2. If Xvfb is already installed, skip to Step 3.
Install Xvfb:
1. Enter the following command to initiate the installation:
  
  $ sudo yum install Xvfb
  
  A password prompt might appear.
2. If a password prompt appears, enter the password for the privileged user account on the application server.
  
  A confirmation prompt appears.
3. Enter Y, and press Enter.
Execute the following cp and chkconfig -add commands to enable Xvfb:
```
$ sudo su - root
# cp <INSTALL_DIR>/service/xvfb /etc/rc.d/init.d
# /sbin/chkconfig --add xvfb
```
where <INSTALL_DIR> is the Oracle Empirica Signal installation directory. For more information, see Unpack the installation files into the installation directory.
Execute the chkconfig --list command to verify that the installation was successful, for example:
# /sbin/chkconfig --list xvfb
The following response appears:

xvfb 0:off 1:off 2:off 3:on 4:off 5:on 6:off
Execute the start command to start Xvfb, for example:
# /etc/rc.d/init.d/xvfb start

The following response appears:
```
Starting xvfb (via systemctl) in Linux 7
Starting X Virtual Frame Buffer in Linux 6
```
Enter exit to terminate your session as the root user.

Parent topic: Prepare the application server