RCHE Red Hat Certified Engineer Linux Study Guide[c] Exam (Rh302)

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.

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.