Troubleshooting Installation

The description of troubleshooting your Fedora or RHEL installation is split into three different areas. The first is what to try if you fail to install Fedora or RHEL. Next, there's what to do if it installs , but fails to boot up. The final area describes how to go forward if Fedora or RHEL is basically working, but selected features or hardware components aren't working.

Insert your Fedora or RHEL boot media and reboot your computer. If your computer bypasses the DVD or CD completely and boots right from hard disk, you may need to change the BIOS (as described earlier in this chapter). If the DVD or CD drive keeps blinking, but doesn't install, you may either have a bad DVD or CD or you might have an older drive that can't use DMA (in the latter case, try linux nodma at the boot prompt). If it hangs at some point during the install, there are many boot options to try, in case the install is hanging on a bad or non-recognized hardware item (see descriptions of boot options earlier in the chapter).

If the computer seems to install properly, but you are unable to boot either your Linux or, perhaps, a Windows system (for a dual-boot computer), there could be a problem with the kernel not recognizing your disk partition boundaries properly. This was a big problem with dual-boot systems in earlier Fedora versions. Even though this problem seems to have been solved , here are a few links you can check out if you are unable to boot Linux or Windows after installing:

• Solutions to the Windows, FC2 Dual Boot Problem ( www.ces.clemson.edu/linux/fc2.shtml )

• Will not boot to Windows Partition using GRUB menu ( http://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=115980 )

If you were able to boot Fedora or RHEL, you can see how the installation went by checking different aspects of your system. There are three log files to look at once the system comes up:

• /root/upgrade.log - When upgrading packages, output from each installed package is sent to this file. You can see what packages were installed and if any failed.

• /var/log/dmesg - This file contains the messages that are sent to the console terminal as the system boots up, including messages relating to the kernel being started and hardware being recognized. If a piece of hardware isn't working, you can check here to make sure that the kernel found the hardware and configured it properly.

• /var/log/boot.log - This file contains information about each service that is started up at boot time. You can see if each service started successfully. If a service fails to start properly, there may be clues in this file that will help you learn what went wrong.

If something was set wrong (such as your mouse) or just isn't working quite right (such as your video display), you can always go back after Fedora is running and correct the problem. Here is a list of utilities you can use to reconfigure different features that were set during installation:

• Changing or adding a mouse - mouse-test

• Changing a keyboard language - system-config-keyboard

• Adding or deleting software packages - yum, Package Updater, system-config-packages or rpm

• Partitioning - fdisk or sfdisk

• Boot loader - /boot/grub/grub.conf (for GRUB); lilo and /etc/lilo.conf (for LILO)

• Networking (Ethernet & TCP/IP) - system-config-network

• Time zone - timeconfig or firstboot

• User accounts - useradd or system-config-users

• Sound - system-config-soundcard

• X Window System - system-config-display

Here are a few other random tips that can help you during installation:

• If installation fails because the installation procedure is unable to detect your video card, try restarting installation in text mode. After Fedora Core is installed and running, use the system-config-display command to configure your video card and monitor. (For some cards, such as those from NVIDIA, you need to get and install special drivers from the manufacturer's Web site or rpm.livna.org .)

  Caution 

  Some video card drivers from NVIDIA and ATI will overwrite important Xorg driver files. If you later change to a different video card, features of the new card (such as DRI) might fail. The solution is to entirely remove the NVIDIA or ATI drivers and reinstall your xorg and mesa packages.

• If installation completes successfully, but your screen is garbled when you reboot, you should try to get Fedora or RHEL to boot to a text-login prompt. To do this, add the number 3 to the end of the kernel boot line in GRUB. Linux will start with the GUI temporarily disabled. Run system-config-display to try to fix the problem. (See Chapter 3 for other advice related to fixing your GUI.)

• If your mouse is not detected during installation, you can use arrow keys and the Tab key to make selections. Then use mouse-test to track down the problem.

• If installation improperly probes your hardware or turns on a feature that causes problems with your hardware, you might be able to solve the problem by disabling the offending feature at the install boot prompt. Try adding one or more of the following after the word linux at the installation boot prompt: ide=nodma (if your system hangs while downloading the image), apm=off or acpi=off (if you experience random failures during install), or nousb, nopcmcia , or nofirewire (if you suspect that install is hanging on devices of those types).

• If you are still having problems installing Fedora, try searching FedoraForum.org to see if they have an answer. Sign up for an account and you can ask a question yourself. Probably the best resource for troubleshooting your installation problems for RHEL systems is the Red Hat Support site ( www.redhat.com/apps/support ). Links from that page can take you to documentation, updates and errata, and information about support programs. If you are having problems with a particular piece of hardware, try searching the Solutions Database, using the name of the hardware in the search box. If you are having problems with particular hardware, chances are someone else did, too.