Certification Objective 6.02: X Font Server

---

Assuming your X Server is properly configured, you should be able to start a GUI with the startx command. One of the things that could go wrong is with the X Font Server. The X Window System needs fonts. Linux manages fonts through the X Font Server. RHEL 3 manages the X Font Server with the xfs service script. Generally, you can't start the Linux GUI unless xfs is running. Many different fonts are normally available in the /usr/X1R6/lib/X11/fonts directory.

The X Font Server can be an Achilles' heel for X Window. A number of things can go wrong with xfs. If you can't start your X Window, check the status of your X Font Server with the following command:

# service xfs status 

If the X Font Server is not running, you'll want to go through the following troubleshooting list:

• The xfs service could be stopped or dead. In this case, you may need to try restarting xfs.

• The xfs service might not be set to start in your current runlevel; you can inspect and change this with the appropriate chkconfig command.

• The filesystems with /tmp or /home could be full. The xfs service can't start if either of these filesystems is full. There may also be problems if /tmp is on a different physical hard disk from other X Window files.

  On The Job 

  Do not confuse the X Font Server service script, xfs, with the filesystem with the same initials, which was developed for very large files by Silicon Graphics.

• Fonts could be misconfigured in /etc/X11/XF86Config.

• Fonts could be missing from the default /usr/X1R6/lib/X11/fonts directory. For example, missing 100-dpi or 75-dpi fonts could cause applications in a Linux GUI to look strange.

Any of these problems could make it impossible for you to start a Linux X Window. In addition, if you've set up a default X Window login, these problems could keep you from getting to the graphical login manager.

Exam Watch 

The GUI doesn't work unless xfs has started in your current runlevel. For example, if xfs isn't running in runlevel 3, the startx command won't work from that runlevel.

Exercise 6-3: X Font Server

In this exercise, we'll look at the effect of a problem with the X Font Server on starting the GUI in Linux.

1. If you're in the GUI, exit from it. If you've configured RHEL 3 to start from the text login interface by default, that is easy. Just click Main Menu | Log Out, and click OK to confirm your logout from the GUI.

2. If you have configured RHEL 3 to start the GUI by default, you'll have to open up a command line interface. Right-click on the desktop. In the pop-up menu that appears, click New Terminal, and run the following command:

   # init 3

3. Check on the status of your X Font Server. If your GUI works, it should be operational. Next, deactivate your X Font Server:

   # service xfs status xfs (pid 2560) is running . . . # service xfs stop Shutting down xfs:                     [OK] #

4. Try starting the GUI again with the startx command. Watch what happens. Look for the 'Fatal server' error message.

5. What other things could keep the X Font Server from starting on your computer? Think about elements such as the service configuration utility, or a full /tmp or /home filesystem. You may need to go through this process to diagnose problems during the Red Hat exams.

6. Restart the X Font Server.

---