Troubleshooting the Installation

A standard method for troubleshooting is to gather all available data. Red Hat Linux is a popular operating system. People exchange information about problems online all the time. Once you ve collected data, you can identify the symptoms of the problem and work with the Linux community through your local user group or online.

You can obtain a lot of troubleshooting data by accessing the virtual consoles available during the installation process. The data you collect may indicate one of several major problems, as described in the following section.

Installation Virtual Consoles

One of the key tools for troubleshooting a problem installation is the virtual consoles . Once the graphical installation process begins, you can access five different installation virtual consoles.

When you re having a problem with installation of Red Hat Linux, the problem may not be obvious. There are several text installation screens that can provide valuable messages. You can get to these screens with the Ctrl+Alt+F n command, where n is the virtual console number: 1, 2, 3, 4, 5, or 7. Once you ve reviewed the messages, you can return to the installation screen with the Ctrl+Alt+F7 command. Table 3.22 describes the installation screens.

Table 3.22: Red Hat Installation Screens

Screen

Description

Ctrl+Alt+F1

Looks at the detection messages for the local video card, monitor, and mouse.

Ctrl+Alt+F2

Opens a bash shell with limited command capabilities; for example, the df command can show mounted directories and partitions. Other bash commands are described in Chapters 6 , 7 , and 8 of this book.

Ctrl+Alt+F3

Views the installation log, with messages related to hardware detection; trouble reading CDs or loading drivers may be found here. During the installation process, this information is recorded in /tmp/anaconda.log .

Ctrl+Alt+F4

Goes to the system message log, with messages such as formatting and mounting directories on partitions. During the installation process, this information is recorded in /tmp/syslog .

Ctrl+Alt+F5

Notes other messages, such as filesystem labels, blocks, formats, and journals. Accessible only after Anaconda formats partitions.

Ctrl+Alt+F7

Returns to the graphical installation screen.

Note  

When changing screens during the installation process,some keyboards require that you use the Ctrl and Alt keys on the left side of the keyboard.

Installation virtual consoles and log files in the /tmp/syslog directory are stored in a RAM disk; thus, they are deleted once you reboot your computer or finish the installation process.

Graphics-Detection Messages

Early in this chapter, we reviewed messages in the first console associated with a successful installation. But problems are possible, especially if you have non-conforming graphics hardware. First, let s take a look at a message on my laptop that does not have enough memory:

 You do not have enough RAM to use the graphical installer. Starting text mode. 

This message is straightforward; if you see it, you need a computer with additional memory to perform a graphical installation. Fortunately, text-mode installation (covered in Chapter 04 ) is sufficient for most purposes. Sometimes graphics hardware does not conform, as indicated by the following messages:

 Running anaconda, the Red Hat Linux system installer - please wait... Probing for video card: Unsupported VGA Compatible Probing for monitor type: Unknown monitor Probing for mouse type: Generic - Wheel Mouse (PS/2) Attempting to start native X Server Waiting for X server to start...log located in /tmp/X.log 1...2...3...4...5...X SERVER FAILEDAttempting to start VESA driver X server X   startup failed, falling back to text mode 

These messages are also fairly straightforward, suggesting that this computer does not include graphics hardware that conforms even to the VESA (SVGA) standard.

Log Files

We have surprisingly easy access to log files during the installation process, through the second virtual console. Press Ctrl+Alt+F2 to open a bash prompt:

 -/bin/sh-2.05b# 

Here you can enter the bash commands of your choice. Any files installed so far are accessible through this interface. Earlier, we saw the message for the /tmp/X.log file. Open it with the vi/tmp/X.log command. The file should look similar to Figure 3.75.

click to expand
Figure 3.75: An X Configuration log

Note the comments at the bottom of the file, pointing you to /tmp/ramfs/X.log , which provides additional information about the graphics problem on this computer. Other important log files are readily available in the /tmp directory, as explained in Table 3.23.

Table 3.23: Log Files During the Installation Process

File

Description

anaconda.log

Hardware-detection log associated with the third virtual console

isoinfo

MD5 checksum for the current CD

modules.conf

List of installed modules

syslog

Boot log; corresponds to dmesg (see Chapter 11 )

X.log

Graphical configuration log file

XF86Config.text

Preliminary X Window configuration file

Hardware-Detection Messages

Several; hardware-detection messages are available in the third virtual console. During the installation process, you can get to this console with the Ctrl+Alt+F3 command, or you can see the entire list of messages in the second virtual console in /tmp/anaconda.log . Just remember, as installation proceeds, Anaconda constantly adds information to this file.

If you re having a hardware problem, it will normally be fairly obvious; for example, the following message indicates a problem that Anaconda has reading one of my CD-ROM drives :

 <4>hdb: cdrom_decode_status: error=0x51{DriveReady SeekComplete Error} 

While this message could indicate a problem with the CD media or hardware, it does tend to identify the problem.

Sometimes hardware messages are subtler:

 /tmp/yenta_socket.o: init_module Hint: insmod errors can be caused by incorrect module parameters, including  invalid IO or IRQ parameters. You may find more information in syslog or the output from dmesg. 

I knew that the yenta_socket.o module is related to my PCMCIA hardware; it took additional research to find that my boot disk was missing the i82365 PCMCIA module. It s like the dog that didn t bark; I didn t figure out the problem until I realized that Anaconda never loaded the key PCMCIA module. I wouldn t have figured that out had I not been familiar with the hardware on my laptop.

The System Message Log

The standard Linux installation message log is filled with fairly standard boot messages. It is less likely that you ll see a problem here. For example, any hardware that isn t detected simply does not show up in the system message log.

Thus, in order to find problems through this log, you need to be a bit of a detective. For example, you know there s a problem if you see a message detecting only 128MB of memory when you have 512MB installed.

This log is associated with the fourth installation virtual console, which you can access with the Ctrl+Alt+F4 command. You can also review the messages from the second virtual console in the /tmp/syslog file. Keep in mind that, as installation proceeds, Anaconda constantly adds information to this file.

Other Messages

Anaconda formats your partitions just before it actually starts to install Red Hat Linux. If you haven t configured partitions with sufficient space, you ll get an error message and will have to start the process again. Standard file size requirements associated with each installation option are described earlier in Table 3.6 .

You can take a look at this console after Red Hat Linux starts to install packages on your computer by using the Ctrl+Alt+F5 command. We ve shown a view in Figure 3.76, which includes messages on how Anaconda has formatted the root ( / ) directory filesystem.

click to expand
Figure 3.76: Anaconda format messages

Later in this process, Anaconda presents a GRUB prompt that lets you modify your bootloader configuration. However, the GRUB configuration file, grub.conf , is accessible through the second virtual console, as we described earlier in the "Anaconda Installs Red Hat Linux" section.

Package Status

One all too common problem with Linux installations is an RPM package that wasn t copied correctly. It could be the 1000th package in the installation process. If suddenly Anaconda finds a problem with a specific package, the installation stops. Unless you have alternate media (such as duplicate CDs) at hand, you may have no recourse but to restart the installation.

Once installation proceeds, you can track the status of the installation on the screen. Both graphics- and text-mode installations identify the package currently being installed. There is one more source; once installation starts, you can find the current list through the second virtual console, in the install .log file located in the /mnt/sysimage/root directory.

If you can identify the package with the problem, you may be able to replace it. You could replace it in the list of packages on the CD, or if you re more fortunate, you could download the package again to a central network installation source.

Especially if you ve downloaded your Red Hat installation CDs over the Internet, there are many possible causes. There could be a momentary power surge somewhere on the Internet. You could be downloading to a hard drive with a bad sector. You might copy the CD files onto a disk with a flaw. The possible causes go on and on. While installing Red Hat Linux from downloaded CDs is usually trouble-free (I do it all the time), it does have its share of risks.

 


Mastering Red Hat Linux 9
Building Tablet PC Applications (Pro-Developer)
ISBN: 078214179X
EAN: 2147483647
Year: 2005
Pages: 220

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