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.

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

1. 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.
2. 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.
3. Execute the following enable and daemon-reload commands to enable Xvfb:

   $ sudo su - root
   # cp <INSTALL_DIR>/service/xvfb.service
   /usr/lib/systemd/system
   # cd /usr/lib/systemd/system
   # systemctl enable xvfb.service
   # systemctl daemon-reload

   where <INSTALL_DIR> is the Oracle Empirica Signal installation directory. For more information, see Unpack the installation files into the installation directory.

4. Execute the start command to start Xvfb, for example:

   # systemctl status xvfb.service
   # systemctl start xvfb.service

   The following response appears:

   Started Start Virtual Framebuffer to support generation of Empirica Signal graphs…

5. Enter exit to terminate your session as the root user.