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<html><head><meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"><title>Chapter 9. Common Problems and Their Solutions</title><link rel="stylesheet" href="susebooks.css" type="text/css"><meta name="generator" content="DocBook XSL Stylesheets V1.75.2"><link rel="home" href="index.html" title="Documentation"><link rel="up" href="part.trouble.html" title="Part III. Help and Troubleshooting"><link rel="prev" href="cha.userhelp.html" title="Chapter 8. Help and Documentation"><link rel="next" href="bk01apa.html" title="Appendix A. GNU Licenses"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header" border="0" class="bctable"><tr><td width="80%"><div class="breadcrumbs"><p><a href="index.html"> Documentation</a><span class="breadcrumbs-sep"> > </span><a href="book.opensuse.startup.html">Start-Up</a><span class="breadcrumbs-sep"> > </span><a href="part.trouble.html">Help and Troubleshooting</a><span class="breadcrumbs-sep"> > </span><strong><a accesskey="p" title="Chapter 8. Help and Documentation" href="cha.userhelp.html"><span>◀</span></a> </strong></p></div></td></tr></table></div><div class="chapter" title="Chapter 9. Common Problems and Their Solutions"><div class="titlepage"><div><div><h2 class="title"><a name="cha.trouble"></a>Chapter 9. Common Problems and Their Solutions<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#cha.trouble">¶</a></span></h2></div></div></div><div class="toc"><p><b>Contents</b></p><dl><dt><span class="sect1"><a href="cha.trouble.html#sec.trouble.info">9.1. Finding and Gathering Information</a></span></dt><dt><span class="sect1"><a href="cha.trouble.html#sec.trouble.install">9.2. Installation Problems</a></span></dt><dt><span class="sect1"><a href="cha.trouble.html#sec.trouble.boot">9.3. Boot Problems</a></span></dt><dt><span class="sect1"><a href="cha.trouble.html#sec.trouble.login">9.4. Login Problems</a></span></dt><dt><span class="sect1"><a href="cha.trouble.html#sec.trouble.netconfig">9.5. Network Problems</a></span></dt><dt><span class="sect1"><a href="cha.trouble.html#sec.trouble.data">9.6. Data Problems</a></span></dt></dl></div><p>
This chapter describes a range of potential problems and their solutions.
Even if your situation is not precisely listed here, there may be one
similar enough to offer hints to the solution of your problem.
</p><div class="sect1" title="9.1. Finding and Gathering Information"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="sec.trouble.info"></a>9.1. Finding and Gathering Information<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.info">¶</a></span></h2></div></div></div><p>
Linux reports things in a very detailed way. There are several places to
look when you encounter problems with your system, most of which are
standard to Linux systems in general, and some of which are relevant to
openSUSE systems. The two most important system logs are
<code class="filename">/var/log/boot.msg</code> and
<code class="filename">/var/log/messages</code>.
</p><p>
A list of the most frequently checked log files follows with the
description of their typical purpose. Paths containing
<code class="filename">~</code> refer to the current user's home directory.
</p><div class="table"><a name="tab.trouble.info"></a><p class="title"><b>Table 9.1. Log Files</b><span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#tab.trouble.info">¶</a></span></p><div class="table-contents"><table summary="Log Files" border="1"><colgroup><col><col></colgroup><thead><tr><th>
<p>
Log File
</p>
</th><th>
<p>
Description
</p>
</th></tr></thead><tbody><tr><td>
<p>
<code class="filename">~/.xsession-errors</code>
</p>
</td><td>
<p>
Messages from the desktop applications currently running.
</p>
</td></tr><tr><td>
<p>
<code class="filename">/var/log/apparmor/</code>
</p>
</td><td>
<p>
Log files from AppArmor, see Part “Confining Privileges with Novell AppArmor” (↑Security Guide) for
detailed information.
</p>
</td></tr><tr><td>
<p>
<code class="filename">/var/log/boot.msg</code>
</p>
</td><td>
<p>
Messages from the kernel reported during the boot process.
</p>
</td></tr><tr><td>
<p>
<code class="filename">/var/log/mail.*</code>
</p>
</td><td>
<p>
Messages from the mail system.
</p>
</td></tr><tr><td>
<p>
<code class="filename">/var/log/messages</code>
</p>
</td><td>
<p>
Ongoing messages from the kernel and system log daemon (when
running).
</p>
</td></tr><tr><td>
<p>
<code class="filename">/var/log/NetworkManager</code>
</p>
</td><td>
<p>
Log file from NetworkManager to collect problems with network connectivity
</p>
</td></tr><tr><td>
<p>
<code class="filename">/var/log/samba/</code>
</p>
</td><td>
<p>
Directory containing Samba server and client log messages.
</p>
</td></tr><tr><td>
<p>
<code class="filename">/var/log/SaX.log</code>
</p>
</td><td>
<p>
Hardware messages from the SaX display and KVM system.
</p>
</td></tr><tr><td>
<p>
<code class="filename">/var/log/warn</code>
</p>
</td><td>
<p>
All messages from the kernel and system log daemon with the
<span class="quote">“<span class="quote">warning</span>”</span> level or higher.
</p>
</td></tr><tr><td>
<p>
<code class="filename">/var/log/wtmp</code>
</p>
</td><td>
<p>
Binary file containing user login records for the current machine
session. View it with <span class="command"><strong>last</strong></span>.
</p>
</td></tr><tr><td>
<p>
<code class="filename">/var/log/Xorg.*.log</code>
</p>
</td><td>
<p>
Various start-up and runtime logs from the X Window system. It is
useful for debugging failed X start-ups.
</p>
</td></tr><tr><td>
<p>
<code class="filename">/var/log/YaST2/</code>
</p>
</td><td>
<p>
Directory containing YaST's actions and their results.
</p>
</td></tr><tr><td>
<p>
<code class="filename">/var/log/zypper.log</code>
</p>
</td><td>
<p>
Log file of zypper.
</p>
</td></tr></tbody></table></div></div><br class="table-break"><p>
Apart from log files, your machine also supplies you with information
about the running system. See
<a class="xref" href="cha.trouble.html#tab.trouble.system" title="Table 9.2. System Information With the /proc File System">Table 9.2: System Information With the <code class="filename">/proc</code> File System</a>
</p><div class="table"><a name="tab.trouble.system"></a><p class="title"><b>Table 9.2. System Information With the <code class="filename">/proc</code> File System</b><span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#tab.trouble.system">¶</a></span></p><div class="table-contents"><table summary="System Information With the /proc File System" border="1"><colgroup><col><col></colgroup><thead><tr><th>
<p>
File
</p>
</th><th>
<p>
Description
</p>
</th></tr></thead><tbody><tr><td>
<p>
<code class="filename">/proc/cpuinfo</code>
</p>
</td><td>
<p>
Contains processor information, including its type, make, model, and
performance.
</p>
</td></tr><tr><td>
<p>
<code class="filename">/proc/dma</code>
</p>
</td><td>
<p>
Shows which DMA channels are currently being used.
</p>
</td></tr><tr><td>
<p>
<code class="filename">/proc/interrupts</code>
</p>
</td><td>
<p>
Shows which interrupts are in use, and how many of each have been in
use.
</p>
</td></tr><tr><td>
<p>
<code class="filename">/proc/iomem</code>
</p>
</td><td>
<p>
Displays the status of I/O (input/output) memory.
</p>
</td></tr><tr><td>
<p>
<code class="filename">/proc/ioports</code>
</p>
</td><td>
<p>
Shows which I/O ports are in use at the moment.
</p>
</td></tr><tr><td>
<p>
<code class="filename">/proc/meminfo</code>
</p>
</td><td>
<p>
Displays memory status.
</p>
</td></tr><tr><td>
<p>
<code class="filename">/proc/modules</code>
</p>
</td><td>
<p>
Displays the individual modules.
</p>
</td></tr><tr><td>
<p>
<code class="filename">/proc/mounts</code>
</p>
</td><td>
<p>
Displays devices currently mounted.
</p>
</td></tr><tr><td>
<p>
<code class="filename">/proc/partitions</code>
</p>
</td><td>
<p>
Shows the partitioning of all hard disks.
</p>
</td></tr><tr><td>
<p>
<code class="filename">/proc/version</code>
</p>
</td><td>
<p>
Displays the current version of Linux.
</p>
</td></tr></tbody></table></div></div><br class="table-break"><p>
Apart from the <code class="filename">/proc</code> file system, the Linux kernel
exports information with the <code class="literal">sysfs</code> module, an
in-memory filesystem. This module represents kernel objects, their
attributes and relationships. For more information about
<code class="literal">sysfs</code>, see the context of udev in
Chapter <i>Dynamic Kernel Device Management with <code class="systemitem">udev</code></i> (↑Reference).
<a class="xref" href="cha.trouble.html#tab.trouble.sysfs" title="Table 9.3. System Information With the /sys File System">Table 9.3</a>
contains an overview of the most common directories under
<code class="filename">/sys</code>.
</p><div class="table"><a name="tab.trouble.sysfs"></a><p class="title"><b>Table 9.3. System Information With the <code class="filename">/sys</code> File System</b><span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#tab.trouble.sysfs">¶</a></span></p><div class="table-contents"><table summary="System Information With the /sys File System" border="1"><colgroup><col><col></colgroup><thead><tr><th>
<p>
File
</p>
</th><th>
<p>
Description
</p>
</th></tr></thead><tbody><tr><td>
<p>
<code class="filename">/sys/block</code>
</p>
</td><td>
<p>
Contains subdirectories for each block device discovered in the
system. Generally, these are mostly disk type devices.
</p>
</td></tr><tr><td>
<p>
<code class="filename">/sys/bus</code>
</p>
</td><td>
<p>
Contains subdirectories for each physical bus type.
</p>
</td></tr><tr><td>
<p>
<code class="filename">/sys/class</code>
</p>
</td><td>
<p>
Contains subdirectories grouped together as a functional types of
devices (like graphics, net, printer, etc.)
</p>
</td></tr><tr><td>
<p>
<code class="filename">/sys/device</code>
</p>
</td><td>
<p>
Contains the global device hierarchy.
</p>
</td></tr></tbody></table></div></div><br class="table-break"><p>
Linux comes with a number of tools for system analysis and monitoring.
See Chapter <i>System Monitoring Utilities</i> (↑Reference) for a selection of the most important ones
used in system diagnostics.
</p><p>
Each of the following scenarios begins with a header describing the
problem followed by a paragraph or two offering suggested solutions,
available references for more detailed solutions, and cross-references to
other scenarios that are related.
</p></div><div class="sect1" title="9.2. Installation Problems"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="sec.trouble.install"></a>9.2. Installation Problems<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.install">¶</a></span></h2></div></div></div><p>
Installation problems are situations when a machine fails to install. It
may fail entirely or it may not be able to start the graphical installer.
This section highlights some of the typical problems you may run into,
and offers possible solutions or workarounds for these kinds of
situations.
</p><div class="sect2" title="9.2.1. Checking Media"><div class="titlepage"><div><div><h3 class="title"><a name="sec.trouble.checkingMedia"></a>9.2.1. Checking Media<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.checkingMedia">¶</a></span></h3></div></div></div><a class="indexterm" name="id369522"></a><a class="indexterm" name="id369530"></a><p>
If you encounter any problems using the openSUSE installation
media, check the integrity of your installation media. Boot from the
media and choose <span class="guimenu">Check Installation Media</span> from the
boot menu. In a running system, start YaST and choose <span class="guimenu">Software</span>+<span class="guimenu">Media Check</span>. Media problems are more probable with the media you burn
yourself. Burning the media at a low speed (4x) helps avoiding problems.
</p></div><div class="sect2" title="9.2.2. Hardware Information"><div class="titlepage"><div><div><h3 class="title"><a name="sec.trouble.hardinfo"></a>9.2.2. Hardware Information<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.hardinfo">¶</a></span></h3></div></div></div><a class="indexterm" name="id369573"></a><a class="indexterm" name="id369582"></a><p>
Display detected hardware and technical data using <span class="guimenu">Hardware</span>+<span class="guimenu">Hardware Information</span> in YaST. Click any node of the tree for more information
about a device. This module is especially useful, when submitting a
support request for which you need information about your hardware.
</p><p>
Save the displayed hardware information to a file by clicking
<span class="guimenu">Save to File</span>. Select the desired directory and
filename then click <span class="guimenu">Save</span> to create the file.
</p></div><div class="sect2" title="9.2.3. No Bootable DVD Drive Available"><div class="titlepage"><div><div><h3 class="title"><a name="sec.trouble.install.cdrom"></a>9.2.3. No Bootable DVD Drive Available<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.install.cdrom">¶</a></span></h3></div></div></div><p>
If your computer does not contain a bootable DVD-ROM drive or if the one
you have is not supported by Linux, there are several options you can
install your machine without a built-in DVD drive:
</p><div class="variablelist"><dl><dt><span class="term">Using an External Boot Device</span></dt><dd><p>
If it is supported by your BIOS and the installation kernel, boot
from external DVD drives or USB storage devices.
</p></dd><dt><span class="term">Network Boot via PXE</span></dt><dd><p>
If a machine lacks a DVD drive, but provides a working ethernet
connection, perform a completely network-based installation. See
Section “Remote Installation via VNC—PXE Boot and Wake on LAN” (Chapter 1, <i>Remote Installation</i>, ↑Reference) and
Section “Remote Installation via SSH—PXE Boot and Wake on LAN” (Chapter 1, <i>Remote Installation</i>, ↑Reference) for
details.
</p></dd></dl></div><div class="sect3" title="9.2.3.1. External Boot Devices"><div class="titlepage"><div><div><h4 class="title"><a name="sec.trouble.install.cdrom.ext"></a>9.2.3.1. External Boot Devices<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.install.cdrom.ext">¶</a></span></h4></div></div></div><p>
Linux supports most existing DVD drives. If the system has neither a
DVD drive nor a floppy disk, it is still possible that an external DVD
drive, connected through USB, FireWire, or SCSI, can be used to boot
the system. This depends mainly on the interaction of the BIOS and the
hardware used. Sometimes a BIOS update may help if you encounter
problems.
</p><p>
When installing from a KDE or GNOME Live CD, you can also create a
<span class="quote">“<span class="quote">Live USB stick</span>”</span> to boot from. Refer to
<a class="ulink" href="http://en.opensuse.org/Live_USB_stick" target="_top">http://en.opensuse.org/Live_USB_stick</a> for detailed
instructions.
</p></div></div><div class="sect2" title="9.2.4. Booting from Installation Media Fails"><div class="titlepage"><div><div><h3 class="title"><a name="sec.trouble.install.BIOS"></a>9.2.4. Booting from Installation Media Fails<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.install.BIOS">¶</a></span></h3></div></div></div><a class="indexterm" name="id369733"></a><a class="indexterm" name="id369742"></a><p>
One reason why a machine does not boot the installation media can be an
incorrect boot sequence setting in BIOS. The BIOS boot sequence must
have DVD drive set as the first entry for booting. Otherwise the machine
would try to boot from another medium, typically the hard disk. Guidance
for changing the BIOS boot sequence can be found the documentation
provided with your motherboard, or in the following paragraphs.
</p><p>
The BIOS is the software that enables the very basic functions of a
computer. Motherboard vendors provide a BIOS specifically made for their
hardware. Normally, the BIOS setup can only be accessed at a specific
time—when the machine is booting. During this initialization
phase, the machine performs a number of diagnostic hardware tests. One
of them is a memory check, indicated by a memory counter. When the
counter appears, look for a line, usually below the counter or somewhere
at the bottom, mentioning the key to press to access the BIOS setup.
Usually the key to press is one of <span class="keycap">Del</span>,
<span class="keycap">F1</span>, or <span class="keycap">Esc</span>. Press this key until the
BIOS setup screen appears.
</p><div class="procedure" title="Procedure 9.1. Changing the BIOS Boot Sequence"><a name="proc.trouble.install.bios"></a><p class="title"><b>Procedure 9.1. Changing the BIOS Boot Sequence</b><span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#proc.trouble.install.bios">¶</a></span></p><ol class="procedure" type="1"><li><p>
Enter the BIOS using the proper key as announced by the boot routines
and wait for the BIOS screen to appear.
</p></li><li><p>
To change the boot sequence in an AWARD BIOS, look for the
<span class="guimenu">BIOS FEATURES SETUP</span> entry. Other manufacturers may
have a different name for this, such as <span class="guimenu">ADVANCED CMOS
SETUP</span>. When you have found the entry, select it and confirm
with <span class="keycap">Enter</span>.
</p></li><li><p>
In the screen that opens, look for a subentry called <span class="guimenu">BOOT
SEQUENCE</span> or <span class="guimenu">BOOT ORDER</span>. The boot sequence
looks something like <code class="literal">C,A</code> or <code class="literal">A,C</code>.
In the former case, the machine first searches the hard disk (C) then
the floppy drive (A) to find a bootable medium. Change the settings by
pressing <span class="keycap">PgUp</span> or <span class="keycap">PgDown</span> until the
sequence is <code class="literal">A,CDROM,C</code>.
</p></li><li><p>
Leave the BIOS setup screen by pressing <span class="keycap">Esc</span>. To save
the changes, select <span class="guimenu">SAVE & EXIT SETUP</span>, or press
<span class="keycap">F10</span>. To confirm that your settings should be saved,
press <span class="keycap">Y</span>.
</p></li></ol></div><div class="procedure" title="Procedure 9.2. Changing the Boot Sequence in a SCSI BIOS (Adaptec Host Adapter)"><a name="id369888"></a><p class="title"><b>Procedure 9.2. Changing the Boot Sequence in a SCSI BIOS (Adaptec Host Adapter)</b></p><ol class="procedure" type="1"><li><p>
Open the setup by pressing <span class="keycap">Ctrl</span>+<span class="keycap">A</span>.
</p></li><li><p>
Select <span class="guimenu">Disk Utilities</span>. The connected hardware
components are now displayed.
</p><p>
Make note of the SCSI ID of your DVD drive.
</p></li><li><p>
Exit the menu with <span class="keycap">Esc</span>.
</p></li><li><p>
Open <span class="guimenu">Configure Adapter Settings</span>. Under
<span class="guimenu">Additional Options</span>, select <span class="guimenu">Boot Device
Options</span> and press <span class="keycap">Enter</span>.
</p></li><li><p>
Enter the ID of the DVD drive and press <span class="keycap">Enter</span> again.
</p></li><li><p>
Press <span class="keycap">Esc</span> twice to return to the start screen of the
SCSI BIOS.
</p></li><li><p>
Exit this screen and confirm with <span class="guimenu">Yes</span> to boot the
computer.
</p></li></ol></div><p>
Regardless of what language and keyboard layout your final installation
will be using, most BIOS configurations use the US keyboard layout as
depicted in the following figure: <a class="indexterm" name="id370018"></a>
</p><div class="figure"><a name="fig.trouble.install.keyboard_us"></a><p class="title"><b>Figure 9.1. US Keyboard Layout</b><span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#fig.trouble.install.keyboard_us">¶</a></span></p><div class="figure-contents"><div class="mediaobject"><table border="0" summary="manufactured viewport for HTML img" cellspacing="0" cellpadding="0" width="75%"><tr><td><img src="images/keyboard_us.png" width="100%" alt="US Keyboard Layout"></td></tr></table></div></div></div><br class="figure-break"></div><div class="sect2" title="9.2.5. Fails to Boot"><div class="titlepage"><div><div><h3 class="title"><a name="sec.trouble.install.noboot"></a>9.2.5. Fails to Boot<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.install.noboot">¶</a></span></h3></div></div></div><p>
Some hardware types, mainly very old or very recent ones, fail to
install. In many cases, this may happen because support for this type of
hardware is missing in the installation kernel, or due to certain
functionality included in this kernel, such as ACPI, that can still
cause problems on some hardware.
</p><p>
If your system fails to install using the standard
<span class="guimenu">Installation</span> mode from the first installation boot
screen, try the following:
</p><div class="procedure"><ol class="procedure" type="1"><li><p>
With the DVD still in the drive, reboot the machine with
<span class="keycap">Ctrl</span>-<span class="keycap">Alt</span>-<span class="keycap">Del</span> or using the
hardware reset button.
</p></li><li><p>
When the boot screen appears, press <span class="keycap">F5</span>, use the arrow
keys of your keyboard to navigate to <span class="guimenu">No ACPI</span> and
press <span class="keycap">Enter</span> to launch the boot and
installation process. This option disables the support for ACPI power
management techniques.
</p></li><li><p>
Proceed with the installation as described in
<a class="xref" href="cha.inst.html" title="Chapter 1. Installation with YaST">Chapter 1, <i>Installation with YaST</i></a>.
</p></li></ol></div><p>
If this fails, proceed as above, but choose <span class="guimenu">Safe
Settings</span> instead. This option disables ACPI and DMA support.
Most hardware will boot with this option.
</p><p>
If both of these options fail, use the boot options prompt to pass any
additional parameters needed to support this type of hardware to the
installation kernel. For more information about the parameters available
as boot options, refer to the kernel documentation located in
<code class="filename">/usr/src/linux/Documentation/kernel-parameters.txt</code>.
</p><div class="tip"><table border="0" cellpadding="3" cellspacing="0" width="100%" summary="Tip: Obtaining Kernel Documentation"><tr class="head"><td width="32"><img alt="[Tip]" src="admon/tip.png"></td><th align="left">Obtaining Kernel Documentation</th></tr><tr><td colspan="2" align="left" valign="top"><p>
Install the <code class="systemitem">kernel-source</code>
package to view the kernel documentation.
</p></td></tr></table></div><p>
There are various other ACPI-related kernel parameters that can be
entered at the boot prompt prior to booting for installation:
</p><div class="variablelist"><dl><dt><span class="term"><code class="systemitem">acpi=off</code>
</span></dt><dd><p>
This parameter disables the complete ACPI subsystem on your computer.
This may be useful if your computer cannot handle ACPI at all or if
you think ACPI in your computer causes trouble.
</p></dd><dt><span class="term"><code class="systemitem">acpi=force</code>
</span></dt><dd><p>
Always enable ACPI even if your computer has an old BIOS dated before
the year 2000. This parameter also enables ACPI if it is set in
addition to <code class="systemitem">acpi=off</code>.
</p></dd><dt><span class="term"><code class="systemitem">acpi=noirq</code>
</span></dt><dd><p>
Do not use ACPI for IRQ routing.
</p></dd><dt><span class="term"><code class="systemitem">acpi=ht</code>
</span></dt><dd><p>
Run only enough ACPI to enable hyper-threading.
</p></dd><dt><span class="term"><code class="systemitem">acpi=strict</code>
</span></dt><dd><p>
Be less tolerant of platforms that are not strictly ACPI
specification compliant.
</p></dd><dt><span class="term"><code class="systemitem">pci=noacpi</code>
</span></dt><dd><p>
Disable PCI IRQ routing of the new ACPI system.
</p></dd><dt><span class="term"><code class="systemitem">pnpacpi=off</code>
</span></dt><dd><p>
This option is for serial or parallel problems when your BIOS setup
contains wrong interrupts or ports.
</p></dd><dt><span class="term"><code class="systemitem">notsc</code>
</span></dt><dd><p>
Disable the time stamp counter. This option can be used to work
around timing problems on your systems. It is a recent feature, if
you see regressions on your machine, especially time related or even
total hangs, this option is worth a try.
</p></dd><dt><span class="term"><code class="systemitem">nohz=off</code>
</span></dt><dd><p>
Disable the nohz feature. If your machine hangs, this option may
help. Otherwise it is of no use.
</p></dd></dl></div><p>
Once you have determined the right parameter combination, YaST
automatically writes them to the boot loader configuration to make sure
that the system boots properly next time.
</p><p>
If unexplainable errors occur when the kernel is loaded or during the
installation, select <span class="guimenu">Memory Test</span> in the boot menu to
check the memory. If <span class="guimenu">Memory Test</span> returns an error, it
is usually a hardware error.
</p></div><div class="sect2" title="9.2.6. Fails to Launch Graphical Installer"><div class="titlepage"><div><div><h3 class="title"><a name="sec.trouble.install.graph"></a>9.2.6. Fails to Launch Graphical Installer<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.install.graph">¶</a></span></h3></div></div></div><p>
After you insert the medium into your drive and reboot your machine, the
installation screen comes up, but after you select
<span class="guimenu">Installation</span>, the graphical installer does not start.
</p><p>
There are several ways to deal with this situation:
</p><div class="itemizedlist"><ul class="itemizedlist" type="bullet"><li class="listitem" style="list-style-type: disc"><p>
Try to select another screen resolution for the installation dialogs.
</p></li><li class="listitem" style="list-style-type: disc"><p>
Select <span class="guimenu">Text Mode</span> for installation.
</p></li><li class="listitem" style="list-style-type: disc"><p>
Do a remote installation via VNC using the graphical installer.
</p></li></ul></div><div class="procedure" title="Procedure 9.3. Change Screen Resolution for Installation"><a name="proc.trouble.install.graph"></a><p class="title"><b>Procedure 9.3. Change Screen Resolution for Installation</b><span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#proc.trouble.install.graph">¶</a></span></p><ol class="procedure" type="1"><li><p>
Boot for installation.
</p></li><li><p>
Press <span class="keycap">F3</span> to open a menu from which to select a lower
resolution for installation purposes.
</p></li><li><p>
Select <span class="guimenu">Installation</span> and proceed with the
installation as described in <a class="xref" href="cha.inst.html" title="Chapter 1. Installation with YaST">Chapter 1, <i>Installation with YaST</i></a>.
</p></li></ol></div><div class="procedure" title="Procedure 9.4. Installation in Text Mode"><a name="proc.trouble.install.text"></a><p class="title"><b>Procedure 9.4. Installation in Text Mode</b><span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#proc.trouble.install.text">¶</a></span></p><ol class="procedure" type="1"><li><p>
Boot for installation.
</p></li><li><p>
Press <span class="keycap">F3</span> and select <span class="guimenu">Text Mode</span>.
</p></li><li><p>
Select <span class="guimenu">Installation</span> and proceed with the
installation as described in <a class="xref" href="cha.inst.html" title="Chapter 1. Installation with YaST">Chapter 1, <i>Installation with YaST</i></a>.
</p></li></ol></div><div class="procedure" title="Procedure 9.5. VNC Installation"><a name="proc.trouble.install.vnc"></a><p class="title"><b>Procedure 9.5. VNC Installation</b><span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#proc.trouble.install.vnc">¶</a></span></p><ol class="procedure" type="1"><li><p>
Boot for installation.
</p></li><li><p>
Enter the following text at the boot options prompt:
</p><pre class="screen">vnc=1 vncpassword=<em class="replaceable"><code>some_password</code></em></pre><p>
Replace <em class="replaceable"><code>some_password</code></em> with the password to
use for VNC installation.
</p></li><li><p>
Select <span class="guimenu">Installation</span> then press
<span class="keycap">Enter</span> to start the installation .
</p><p>
Instead of starting right into the graphical installation routine, the
system continues to run in a text mode, then halts, displaying a
message containing the IP address and port number at which the
installer can be reached via a browser interface or a VNC viewer
application.
</p></li><li><p>
If using a browser to access the installer, launch the browser and
enter the address information provided by the installation routines on
the future openSUSE machine and hit
<span class="keycap">Enter</span>:
</p><pre class="screen">http://<em class="replaceable"><code>ip_address_of_machine</code></em>:5801</pre><p>
A dialog opens in the browser window prompting you for the VNC
password. Enter it and proceed with the installation as described in
<a class="xref" href="cha.inst.html" title="Chapter 1. Installation with YaST">Chapter 1, <i>Installation with YaST</i></a>.
</p><div class="important"><table border="0" cellpadding="3" cellspacing="0" width="100%" summary="Important"><tr class="head"><td width="32"><img alt="[Important]" src="admon/important.png"></td><th align="left"></th></tr><tr><td colspan="2" align="left" valign="top"><p>
Installation via VNC works with any browser under any operating
system, provided Java support is enabled.
</p></td></tr></table></div><p>
Provide the IP address and password to your VNC viewer when prompted.
A window opens, displaying the installation dialogs. Proceed with the
installation as usual.
</p></li></ol></div></div><div class="sect2" title="9.2.7. Only Minimalistic Boot Screen Started"><div class="titlepage"><div><div><h3 class="title"><a name="sec.trouble.install.mini"></a>9.2.7. Only Minimalistic Boot Screen Started<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.install.mini">¶</a></span></h3></div></div></div><p>
You inserted the medium into the drive, the BIOS routines are finished,
but the system does not start with the graphical boot screen. Instead it
launches a very minimalistic text-based interface. This may happen on
any machine not providing sufficient graphics memory for rendering a
graphical boot screen.
</p><p>
Although the text boot screen looks minimalistic, it provides nearly the
same functionality as the graphical one:
</p><div class="variablelist"><dl><dt><span class="term">Boot Options</span></dt><dd><p>
Unlike the graphical interface, the different boot options cannot be
selected using the cursor keys of your keyboard. The boot menu of the
text mode boot screen offers some keywords to enter at the boot
prompt. These keywords map to the options offered in the graphical
version. Enter your choice and hit
<span class="keycap">Enter</span> to launch the boot process.
</p></dd><dt><span class="term">Custom Boot Options</span></dt><dd><p>
After selecting a boot option, enter the appropriate keyword at the
boot prompt or enter some custom boot options as described in
<a class="xref" href="cha.trouble.html#sec.trouble.install.noboot" title="9.2.5. Fails to Boot">Section 9.2.5, “Fails to Boot”</a>. To launch the
installation process, press <span class="keycap">Enter</span>.
</p></dd><dt><span class="term">Screen Resolutions</span></dt><dd><p>
Use the F keys to determine the screen resolution for installation.
If you need to boot in text mode, choose <span class="keycap">F3</span>.
</p></dd></dl></div></div></div><div class="sect1" title="9.3. Boot Problems"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="sec.trouble.boot"></a>9.3. Boot Problems<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.boot">¶</a></span></h2></div></div></div><p>
Boot problems are situations when your system does not boot properly
(does not boot to the expected runlevel and login screen).
</p><div class="sect2" title="9.3.1. Fails to Load the GRUB Boot Loader"><div class="titlepage"><div><div><h3 class="title"><a name="sec.trouble.boot.nogrub"></a>9.3.1. Fails to Load the GRUB Boot Loader<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.boot.nogrub">¶</a></span></h3></div></div></div><p>
If the hardware is functioning properly, it is possible that the boot
loader is corrupted and Linux cannot start on the machine. In this case,
it is necessary to repair the boot loader. To do so, you need start the
Rescue System as described in <a class="xref" href="cha.trouble.html#sec.trouble.data.recover" title="9.6.4. Recovering a Corrupted System">Section 9.6.4, “Recovering a Corrupted System”</a>
and follow the instructions at <a class="xref" href="cha.trouble.html#sec.trouble.data.recover.rescue.grub" title="9.6.4.1.4. Modifying and Reinstalling the Boot Loader">Section 9.6.4.1.4, “Modifying and Reinstalling the Boot Loader”</a>.
</p><p>
Other reasons for the machine not booting may be BIOS-related:
</p><div class="variablelist"><dl><dt><span class="term">BIOS Settings</span></dt><dd><p>
Check your BIOS for references to your hard drive. GRUB may simply
not be started if the hard drive itself cannot be found with the
current BIOS settings.
</p></dd><dt><span class="term">BIOS Boot Order</span></dt><dd><p>
Check whether your system's boot order includes the hard disk. If the
hard disk option was not enabled, your system may install properly,
but fails to boot when access to the hard disk is required.
</p></dd></dl></div></div><div class="sect2" title="9.3.2. No Graphical Login"><div class="titlepage"><div><div><h3 class="title"><a name="sec.trouble.boot.prompt"></a>9.3.2. No Graphical Login<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.boot.prompt">¶</a></span></h3></div></div></div><p>
If the machine comes up, but does not boot into the graphical login
manager, anticipate problems either with the choice of the default
runlevel or the configuration of the X Window System. To check the
runlevel configuration, log in as the
<code class="systemitem">root</code> user and check whether
the machine is configured to boot into runlevel 5 (graphical desktop). A
quick way to check this is to examine the contents of
<code class="filename">/etc/inittab</code>, as follows:
</p><pre class="screen">tux@mercury:~> grep "id:" /etc/inittab
id:5:initdefault:</pre><p>
The returned line indicates that the machine's default runlevel
(<code class="literal">initdefault</code>) is set to <code class="literal">5</code> and that
it should boot to the graphical desktop. If the runlevel is set to any
other number, use the YaST Runlevel Editor module to set it to
<code class="literal">5</code>.
</p><div class="important"><table border="0" cellpadding="3" cellspacing="0" width="100%" summary="Important"><tr class="head"><td width="32"><img alt="[Important]" src="admon/important.png"></td><th align="left"></th></tr><tr><td colspan="2" align="left" valign="top"><p>
Do not edit the runlevel configuration manually. Otherwise SuSEconfig
(run by YaST) will overwrite these changes on its next run. If you
need to make manual changes here, disable future SuSEconfig changes by
setting <em class="replaceable"><code>CHECK_INITTAB</code></em> in
<code class="filename">/etc/sysconfig/suseconfig</code> to <code class="option">no</code>.
</p></td></tr></table></div><p>
If the runlevel is set to <code class="literal">5</code>, your desktop or X
Windows software is probably misconfigured or corrupted. Examine the log
files at <code class="filename">/var/log/Xorg.*.log</code> for detailed messages
from the X server as it attempted to start. If the desktop fails during
start, it may log error messages to
<code class="filename">/var/log/messages</code>. If these error messages hint at
a configuration problem in the X server, try to fix these issues. If the
graphical system still does not come up, consider reinstalling the
graphical desktop.
</p><div class="tip"><table border="0" cellpadding="3" cellspacing="0" width="100%" summary="Tip: Starting X Window System Manually"><tr class="head"><td width="32"><img alt="[Tip]" src="admon/tip.png"></td><th align="left">Starting X Window System Manually</th></tr><tr><td colspan="2" align="left" valign="top"><p>
One quick test: the <span class="command"><strong>startx</strong></span> command should force the
X Window System to start with the configured defaults if the user is
currently logged in on the console. If that does not work, it should
log errors to the console.
</p></td></tr></table></div></div></div><div class="sect1" title="9.4. Login Problems"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="sec.trouble.login"></a>9.4. Login Problems<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.login">¶</a></span></h2></div></div></div><p>
Login problems are those where your machine does, in fact, boot to the
expected welcome screen or login prompt, but refuses to accept the
username and password, or accepts them but then does not behave properly
(fails to start the graphic desktop, produces errors, drops to a command
line, etc.).
</p><div class="sect2" title="9.4.1. Valid Username and Password Combinations Fail"><div class="titlepage"><div><div><h3 class="title"><a name="sec.trouble.login.no"></a>9.4.1. Valid Username and Password Combinations Fail<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.login.no">¶</a></span></h3></div></div></div><p>
This usually occurs when the system is configured to use network
authentication or directory services and, for some reason, is unable to
retrieve results from its configured servers. The
<code class="systemitem">root</code> user, as the only local
user, is the only user that can still log in to these machines. The
following are some common reasons why a machine appears functional but
is unable to process logins correctly:
</p><div class="itemizedlist"><ul class="itemizedlist" type="bullet"><li class="listitem" style="list-style-type: disc"><p>
The network is not working. For further directions on this, turn to
<a class="xref" href="cha.trouble.html#sec.trouble.netconfig" title="9.5. Network Problems">Section 9.5, “Network Problems”</a>.
</p></li><li class="listitem" style="list-style-type: disc"><p>
DNS is not working at the moment (which prevents GNOME or KDE from
working and the system from making validated requests to secure
servers). One indication that this is the case is that the machine
takes an extremely long time to respond to any action. Find more
information about this topic in
<a class="xref" href="cha.trouble.html#sec.trouble.netconfig" title="9.5. Network Problems">Section 9.5, “Network Problems”</a>.
</p></li><li class="listitem" style="list-style-type: disc"><p>
If the system is configured to use Kerberos, the system's local time
may have drifted past the accepted variance with the Kerberos server
time (this is typically 300 seconds). If NTP (network time protocol)
is not working properly or local NTP servers are not working, Kerberos
authentication ceases to function because it depends on common clock
synchronization across the network.
</p></li><li class="listitem" style="list-style-type: disc"><p>
The system's authentication configuration is misconfigured. Check the
PAM configuration files involved for any typographical errors or
misordering of directives. For additional background information about
PAM and the syntax of the configuration files involved, refer to
Chapter <i>Authentication with PAM</i> (↑Security Guide).
</p></li><li class="listitem" style="list-style-type: disc"><p>
The home partition is encrypted. Find more information about this
topic in <a class="xref" href="cha.trouble.html#sec.trouble.login.encrypted" title="9.4.3. Login to Encrypted Home Partition Fails">Section 9.4.3, “Login to Encrypted Home Partition Fails”</a>.
</p></li></ul></div><p>
In all cases that do not involve external network problems, the solution
is to reboot the system into single-user mode and repair the
configuration before booting again into operating mode and attempting to
log in again. To boot into single-user mode:
</p><div class="procedure"><a name="proc.trouble.login.no"></a><ol class="procedure" type="1"><li><p>
Reboot the system. The boot screen appears, offering a prompt.
</p></li><li><p>
Enter <span class="command"><strong>1</strong></span> at the boot prompt to make the system boot
into single-user mode.
</p></li><li><p>
Enter the username and password for
<code class="systemitem">root</code>.
</p></li><li><p>
Make all the necessary changes.
</p></li><li><p>
Boot into the full multiuser and network mode by entering
<span class="command"><strong>telinit 5</strong></span> at the command line.
</p></li></ol></div></div><div class="sect2" title="9.4.2. Valid Username and Password Not Accepted"><div class="titlepage"><div><div><h3 class="title"><a name="sec.trouble.login.pw"></a>9.4.2. Valid Username and Password Not Accepted<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.login.pw">¶</a></span></h3></div></div></div><p>
This is by far the most common problem users encounter, because there
are many reasons this can occur. Depending on whether you use local user
management and authentication or network authentication, login failures
occur for different reasons.
</p><p>
Local user management can fail for the following reasons:
</p><div class="itemizedlist"><ul class="itemizedlist" type="bullet"><li class="listitem" style="list-style-type: disc"><p>
The user may have entered the wrong password.
</p></li><li class="listitem" style="list-style-type: disc"><p>
The user's home directory containing the desktop configuration files
is corrupted or write protected.
</p></li><li class="listitem" style="list-style-type: disc"><p>
There may be problems with the X Window System authenticating this
particular user, especially if the user's home directory has been used
with another Linux distribution prior to installing the current one.
</p></li></ul></div><p>
To locate the reason for a local login failure, proceed as follows:
</p><div class="procedure"><ol class="procedure" type="1"><li><p>
Check whether the user remembered his password correctly before you
start debugging the whole authentication mechanism. If the user may
not remember his password correctly, use the YaST User Management
module to change the user's password. Pay attention to the
<span class="keycap">Caps Lock</span> key and unlock it, if necessary.
</p></li><li><p>
Log in as <code class="systemitem">root</code> and check
<code class="filename">/var/log/messages</code> for error messages of the login
process and of PAM.
</p></li><li><p>
Try to log in from a console (using <span class="keycap">Ctrl</span>+<span class="keycap">Alt</span>+<span class="keycap">F1</span>).
If this is successful, the blame cannot be put on PAM, because it is
possible to authenticate this user on this machine. Try to locate any
problems with the X Window System or the desktop (GNOME or KDE). For
more information, refer to <a class="xref" href="cha.trouble.html#sec.trouble.login.dk" title="9.4.4. Login Successful but GNOME Desktop Fails">Section 9.4.4, “Login Successful but GNOME Desktop Fails”</a> and
<a class="xref" href="cha.trouble.html#sec.trouble.login.kde" title="9.4.5. Login Successful but KDE Desktop Fails">Section 9.4.5, “Login Successful but KDE Desktop Fails”</a>.
</p></li><li><p>
If the user's home directory has been used with another Linux
distribution, remove the <code class="filename">Xauthority</code> file in the
user's home. Use a console login via <span class="keycap">Ctrl</span>+<span class="keycap">Alt</span>+<span class="keycap">F1</span>
and run <span class="command"><strong>rm .Xauthority</strong></span> as this user. This should
eliminate X authentication problems for this user. Try graphical login
again.
</p></li><li><p>
If graphical login still fails, do a console login with <span class="keycap">Ctrl</span>+<span class="keycap">Alt</span>+<span class="keycap">F1</span>.
Try to start an X session on another display—the first one
(<code class="literal">:0</code>) is already in use:
</p><pre class="screen">startx -- :1</pre><p>
This should bring up a graphical screen and your desktop. If it does
not, check the log files of the X Window System
(<code class="filename">/var/log/Xorg.<em class="replaceable"><code>displaynumber</code></em>.log</code>)
or the log file for your desktop applications
(<code class="filename">.xsession-errors</code> in the user's home directory)
for any irregularities.
</p></li><li><p>
If the desktop could not start because of corrupt configuration files,
proceed with <a class="xref" href="cha.trouble.html#sec.trouble.login.dk" title="9.4.4. Login Successful but GNOME Desktop Fails">Section 9.4.4, “Login Successful but GNOME Desktop Fails”</a> or
<a class="xref" href="cha.trouble.html#sec.trouble.login.kde" title="9.4.5. Login Successful but KDE Desktop Fails">Section 9.4.5, “Login Successful but KDE Desktop Fails”</a>.
</p></li></ol></div><p>
The following are some common reasons why network authentication for a
particular user may fail on a specific machine:
</p><div class="itemizedlist"><ul class="itemizedlist" type="bullet"><li class="listitem" style="list-style-type: disc"><p>
The user may have entered the wrong password.
</p></li><li class="listitem" style="list-style-type: disc"><p>
The username exists in the machine's local authentication files and is
also provided by a network authentication system, causing conflicts.
</p></li><li class="listitem" style="list-style-type: disc"><p>
The home directory exists but is corrupt or unavailable. Perhaps it is
write protected or is on a server that is inaccessible at the moment.
</p></li><li class="listitem" style="list-style-type: disc"><p>
The user does not have permission to log in to that particular host in
the authentication system.
</p></li><li class="listitem" style="list-style-type: disc"><p>
The machine has changed hostnames, for whatever reason, and the user
does not have permission to log in to that host.
</p></li><li class="listitem" style="list-style-type: disc"><p>
The machine cannot reach the authentication server or directory server
that contains that user's information.
</p></li><li class="listitem" style="list-style-type: disc"><p>
There may be problems with the X Window System authenticating this
particular user, especially if the user's home has been used with
another Linux distribution prior to installing the current one.
</p></li></ul></div><p>
To locate the cause of the login failures with network authentication,
proceed as follows:
</p><div class="procedure"><a name="proc.trouble.login.pw"></a><ol class="procedure" type="1"><li><p>
Check whether the user remembered their password correctly before you
start debugging the whole authentication mechanism.
</p></li><li><p>
Determine the directory server which the machine relies on for
authentication and make sure that it is up and running and properly
communicating with the other machines.
</p></li><li><p>
Determine that the user's username and password work on other machines
to make sure that his authentication data exists and is properly
distributed.
</p></li><li><p>
See if another user can log in to the misbehaving machine. If another
user can log in without difficulty or if
<code class="systemitem">root</code> can log in, log in and
examine the <code class="filename">/var/log/messages</code> file. Locate the
time stamps that correspond to the login attempts and determine if PAM
has produced any error messages.
</p></li><li><p>
Try to log in from a console (using <span class="keycap">Ctrl</span>+<span class="keycap">Alt</span>+<span class="keycap">F1</span>).
If this is successful, the problem is not with PAM or the directory
server on which the user's home is hosted, because it is possible to
authenticate this user on this machine. Try to locate any problems
with the X Window System or the desktop (GNOME or KDE). For more
information, refer to <a class="xref" href="cha.trouble.html#sec.trouble.login.dk" title="9.4.4. Login Successful but GNOME Desktop Fails">Section 9.4.4, “Login Successful but GNOME Desktop Fails”</a> and
<a class="xref" href="cha.trouble.html#sec.trouble.login.kde" title="9.4.5. Login Successful but KDE Desktop Fails">Section 9.4.5, “Login Successful but KDE Desktop Fails”</a>.
</p></li><li><p>
If the user's home directory has been used with another Linux
distribution, remove the <code class="filename">Xauthority</code> file in the
user's home. Use a console login via <span class="keycap">Ctrl</span>+<span class="keycap">Alt</span>+<span class="keycap">F1</span>
and run <span class="command"><strong>rm .Xauthority</strong></span> as this user. This should
eliminate X authentication problems for this user. Try graphical login
again.
</p></li><li><p>
If graphical login still fails, do a console login with <span class="keycap">Ctrl</span>+<span class="keycap">Alt</span>+<span class="keycap">F1</span>.
Try to start an X session on another display—the first one
(<code class="literal">:0</code>) is already in use:
</p><pre class="screen">startx -- :1</pre><p>
This should bring up a graphical screen and your desktop. If it does
not, check the log files of the X Window System
(<code class="filename">/var/log/Xorg.<em class="replaceable"><code>displaynumber</code></em>.log</code>)
or the log file for your desktop applications
(<code class="filename">.xsession-errors</code> in the user's home directory)
for any irregularities.
</p></li><li><p>
If the desktop could not start because of corrupt configuration files,
proceed with <a class="xref" href="cha.trouble.html#sec.trouble.login.dk" title="9.4.4. Login Successful but GNOME Desktop Fails">Section 9.4.4, “Login Successful but GNOME Desktop Fails”</a> or
<a class="xref" href="cha.trouble.html#sec.trouble.login.kde" title="9.4.5. Login Successful but KDE Desktop Fails">Section 9.4.5, “Login Successful but KDE Desktop Fails”</a>.
</p></li></ol></div></div><div class="sect2" title="9.4.3. Login to Encrypted Home Partition Fails"><div class="titlepage"><div><div><h3 class="title"><a name="sec.trouble.login.encrypted"></a>9.4.3. Login to Encrypted Home Partition Fails<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.login.encrypted">¶</a></span></h3></div></div></div><a class="indexterm" name="id371734"></a><p>
It is recommended to use an encrypted home partition for laptops. If you
cannot log in to your laptop, the reason is usually simple: your
partition could not be unlocked.
</p><p>
During the boot time, you have to enter the passphrase to unlock your
encrypted partition. If you do not enter it, the boot process continues,
leaving the partition locked.
</p><p>
To unlock your encrypted partition, proceed as follows:
</p><div class="procedure"><ol class="procedure" type="1"><li><p>
Switch to the text console with <span class="keycap">Ctrl</span>+<span class="keycap">Alt</span>+<span class="keycap">F1</span>.
</p></li><li><p>
Become <code class="systemitem">root</code>.
</p></li><li><p>
Restart the unlocking process again with:
</p><pre class="screen">/etc/init.d/boot.crypto restart</pre></li><li><p>
Enter your passphrase to unlock your encrypted partition.
</p></li><li><p>
Exit the text console and switch back to the login screen with
<span class="keycap">Alt</span>+<span class="keycap">F7</span>.
</p></li><li><p>
Log in as usual.
</p></li></ol></div></div><div class="sect2" title="9.4.4. Login Successful but GNOME Desktop Fails"><div class="titlepage"><div><div><h3 class="title"><a name="sec.trouble.login.dk"></a>9.4.4. Login Successful but GNOME Desktop Fails<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.login.dk">¶</a></span></h3></div></div></div><p>
If this is the case, it is likely that your GNOME configuration files
have become corrupted. Some symptoms may include the keyboard failing to
work, the screen geometry becoming distorted, or even the screen coming
up as a bare gray field. The important distinction is that if another
user logs in, the machine works normally. It is then likely that the
problem can be fixed relatively quickly by simply moving the user's
GNOME configuration directory to a new location, which causes GNOME to
initialize a new one. Although the user is forced to reconfigure GNOME,
no data is lost.
</p><div class="procedure"><a name="proc.trouble.login.dk"></a><ol class="procedure" type="1"><li><p>
Switch to a text console by pressing <span class="keycap">Ctrl</span>+<span class="keycap">Alt</span>+<span class="keycap">F1</span>.
</p></li><li><p>
Log in with your user name.
</p></li><li><p>
Move the user's GNOME configuration directories to a temporary
location:
</p><pre class="screen">mv .gconf .gconf-ORIG-RECOVER
mv .gnome2 .gnome2-ORIG-RECOVER</pre></li><li><p>
Log out.
</p></li><li><p>
Log in again, but do not run any applications.
</p></li><li><p>
Recover your individual application configuration data (including the
Evolution e-mail client data) by copying the
<code class="filename">~/.gconf-ORIG-RECOVER/apps/</code> directory back into
the new <code class="filename">~/.gconf </code> directory as follows:
</p><pre class="screen">cp -a .gconf-ORIG-RECOVER/apps .gconf/</pre><p>
If this causes the login problems, attempt to recover only the
critical application data and reconfigure the remainder of the
applications.
</p></li></ol></div></div><div class="sect2" title="9.4.5. Login Successful but KDE Desktop Fails"><div class="titlepage"><div><div><h3 class="title"><a name="sec.trouble.login.kde"></a>9.4.5. Login Successful but KDE Desktop Fails<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.login.kde">¶</a></span></h3></div></div></div><p>
There are several reasons why a KDE desktop would not allow users to
login. Corrupted cache data can cause login problems as well as corrupt
KDE desktop configuration files.
</p><p>
Cache data is used at desktop start-up to increase performance. If this
data is corrupted, start-up is slowed down or fails entirely. Removing
them forces the desktop start-up routines to start from scratch. This
takes more time than a normal start-up, but data is intact after this
and the user can login.
</p><p>
To remove the cache files of the KDE desktop, issue the following
command as <code class="systemitem">root</code>:
</p><pre class="screen">rm -rf /tmp/kde-<em class="replaceable"><code>user</code></em> /tmp/ksocket-<em class="replaceable"><code>user</code></em></pre><p>
Replace <em class="replaceable"><code>user</code></em> with your username. Removing
these two directories just removes the corrupted cache files. No real
data is harmed using this procedure.
</p><p>
Corrupted desktop configuration files can always be replaced with the
initial configuration files. If you want to recover the user's
adjustments, carefully copy them back from their temporary location
after the configuration has been restored, using the default
configuration values.
</p><p>
To replace a corrupted desktop configuration with the initial
configuration values, proceed as follows:
</p><div class="procedure"><a name="proc.trouble.login.kde"></a><ol class="procedure" type="1"><li><p>
Switch to a text console by pressing <span class="keycap">Ctrl</span>+<span class="keycap">Alt</span>+<span class="keycap">F1</span>.
</p></li><li><p>
Log in with your username.
</p></li><li id="st.trouble.login.kde.mv"><p>
Move the KDE configuration directory and the
<code class="filename">.skel</code> files to a temporary location:
</p><div class="itemizedlist"><ul class="itemizedlist" type="bullet"><li class="listitem" style="list-style-type: disc"><p>
For KDE3 use these commands:
</p><pre class="screen">mv .kde .kde-ORIG-RECOVER
mv .skel .skel-ORIG-RECOVER<em class="replaceable"><code></code></em></pre></li><li class="listitem" style="list-style-type: disc"><p>
For KDE4 use these commands:
</p><pre class="screen">mv .kde4 .kde4-ORIG-RECOVER
mv .skel .skel-ORIG-RECOVER<em class="replaceable"><code></code></em></pre></li></ul></div></li><li><p>
Log out.
</p></li><li><p>
Log in again.
</p></li><li><p>
After the desktop has started successfully, copy the user's own
configurations back into place:
</p><pre class="screen">cp -a <em class="replaceable"><code>KDEDIR</code></em>/share .kde/share</pre><p>
Replace <em class="replaceable"><code>KDEDIR</code></em> with the directory from
<a class="xref" href="cha.trouble.html#st.trouble.login.kde.mv" title="Step 3">Step 3</a>.
</p><div class="important"><table border="0" cellpadding="3" cellspacing="0" width="100%" summary="Important"><tr class="head"><td width="32"><img alt="[Important]" src="admon/important.png"></td><th align="left"></th></tr><tr><td colspan="2" align="left" valign="top"><p>
If the user's own adjustments caused the login to fail and continue
to do so, repeat the procedure as described above, but do not copy
the <code class="filename">.kde/share</code> directory.
</p></td></tr></table></div></li></ol></div></div></div><div class="sect1" title="9.5. Network Problems"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="sec.trouble.netconfig"></a>9.5. Network Problems<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.netconfig">¶</a></span></h2></div></div></div><p>
Many problems of your system may be network-related, even though they do
not seem to be at first. For example, the reason for a system not
allowing users to log in may be a network problem of some kind. This
section introduces a simple check list you can apply to identify the
cause of any network problem encountered.
</p><div class="procedure" title="Procedure 9.6. How to Identify Network Problems"><a name="proc.trouble.config.net"></a><p class="title"><b>Procedure 9.6. How to Identify Network Problems</b><span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#proc.trouble.config.net">¶</a></span></p><p>
When checking the network connection of your machine, proceed as
follows:
</p><ol class="procedure" type="1"><li><p>
If you use an ethernet connection, check the hardware first. Make sure
that your network cable is properly plugged into your computer and
router (or hub, etc.). The control lights next to your ethernet
connector are normally both be active.
</p><p>
If the connection fails, check whether your network cable works with
another machine. If it does, your network card causes the failure. If
hubs or switches are included in your network setup, they may be
faulty, as well.
</p></li><li><p>
If using a wireless connection, check whether the wireless link can be
established by other machines. If not, contact the wireless network's
administrator.
</p></li><li><p>
Once you have checked your basic network connectivity, try to find out
which service is not responding. Gather the address information of all
network servers needed in your setup. Either look them up in the
appropriate YaST module or ask your system administrator. The
following list gives some of the typical network servers involved in a
setup together with the symptoms of an outage.
</p><div class="variablelist"><dl><dt><span class="term">DNS (Name Service)</span></dt><dd><p>
A broken or malfunctioning name service affects the network's
functionality in many ways. If the local machine relies on any
network servers for authentication and these servers cannot be found
due to name resolution issues, users would not even be able to log
in. Machines in the network managed by a broken name server would
not be able to <span class="quote">“<span class="quote">see</span>”</span> each other and communicate.
</p></dd><dt><span class="term">NTP (Time Service)</span></dt><dd><p>
A malfunctioning or completely broken NTP service could affect
Kerberos authentication and X server functionality.
</p></dd><dt><span class="term">NFS (File Service)</span></dt><dd><p>
If any application needs data stored in an NFS mounted directory, it
will not be able to start or function properly if this service was
down or misconfigured. In the worst case scenario, a user's personal
desktop configuration would not come up if their home directory
containing the <code class="filename">.gconf</code> or
<code class="filename">.kde</code> subdirectories could not be found due to a
faulty NFS server.
</p></dd><dt><span class="term">Samba (File Service)</span></dt><dd><p>
If any application needs data stored in a directory on a faulty
Samba server, it will not be able to start or function properly.
</p></dd><dt><span class="term">NIS (User Management)</span></dt><dd><p>
If your openSUSE system relies on a faulty NIS server to
provide the user data, users will not be able to log in to this
machine.
</p></dd><dt><span class="term">LDAP (User Management)</span></dt><dd><p>
If your openSUSE system relies on a faulty LDAP server to
provide the user data, users will not be able to log in to this
machine.
</p></dd><dt><span class="term">Kerberos (Authentication)</span></dt><dd><p>
Authentication will not work and login to any machine fails.
</p></dd><dt><span class="term">CUPS (Network Printing)</span></dt><dd><p>
Users cannot print.
</p></dd></dl></div></li><li><p>
Check whether the network servers are running and whether your network
setup allows you to establish a connection:
</p><div class="important"><table border="0" cellpadding="3" cellspacing="0" width="100%" summary="Important"><tr class="head"><td width="32"><img alt="[Important]" src="admon/important.png"></td><th align="left"></th></tr><tr><td colspan="2" align="left" valign="top"><p>
The debugging procedure described below only applies to a simple
network server/client setup that does not involve any internal
routing. It assumes both server and client are members of the same
subnet without the need for additional routing.
</p></td></tr></table></div><ol type="a" class="substeps"><li><p>
Use <span class="command"><strong>ping <em class="replaceable"><code>IP address</code></em> or
<em class="replaceable"><code>hostname</code></em></strong></span> (replace
<em class="replaceable"><code>hostname</code></em> with the hostname of the server)
to check whether each one of them is up and responding to the
network. If this command is successful, it tells you that the host
you were looking for is up and running and that the name service for
your network is configured correctly.
</p><p>
If ping fails with <code class="literal">destination host unreachable</code>,
either your system or the desired server is not properly configured
or down. Check whether your system is reachable by running
<span class="command"><strong>ping <em class="replaceable"><code>IP address</code></em> or
<em class="replaceable"><code>your_hostname</code></em> </strong></span> from another
machine. If you can reach your machine from another machine, it is
the server that is not running at all or not configured correctly.
</p><p>
If ping fails with <code class="literal">unknown host</code>, the name service
is not configured correctly or the hostname used was incorrect. For
further checks on this matter, refer to
<a class="xref" href="cha.trouble.html#st.trouble.config.net.host" title="Step 4.b">Step 4.b</a>.
If ping still fails, either your network card is not configured
correctly or your network hardware is faulty.
</p></li><li id="st.trouble.config.net.host"><p>
Use <span class="command"><strong>host <em class="replaceable"><code>hostname</code></em></strong></span> to
check whether the hostname of the server you are trying to connect to
is properly translated into an IP address and vice versa. If this
command returns the IP address of this host, the name service is up
and running. If the <span class="command"><strong>host</strong></span> command fails, check all
network configuration files relating to name and address resolution
on your host:
</p><div class="variablelist"><dl><dt><span class="term"><code class="filename">/etc/resolv.conf</code>
</span></dt><dd><p>
This file is used to keep track of the name server and domain you
are currently using. It can be modified manually or automatically
adjusted by YaST or DHCP. Automatic adjustment is preferable.
However, make sure that this file has the following structure and
all network addresses and domain names are correct:
</p><pre class="screen">search <em class="replaceable"><code>fully_qualified_domain_name</code></em>
nameserver <em class="replaceable"><code>ipaddress_of_nameserver</code></em></pre><p>
This file can contain more than one name server address, but at
least one of them must be correct to provide name resolution to
your host. If needed, adjust this file using the YaST Network
Setting module (Hostname/DNS tab).
</p><p>
If your network connection is handled via DHCP, enable DHCP to
change hostname and name service information by selecting
<span class="guimenu">Change Hostname via DHCP</span> and <span class="guimenu">Update
Name Servers and Search List via DHCP</span> in the YaST DNS
and Hostname module.
</p></dd><dt><span class="term"><code class="filename">/etc/nsswitch.conf</code>
</span></dt><dd><p>
This file tells Linux where to look for name service information.
It should look like this:
</p><pre class="screen"> ...
hosts: files dns
networks: files dns
...</pre><p>
The <code class="option">dns</code> entry is vital. It tells Linux to use an
external name server. Normally, these entries are automatically
managed by YaST, but it would be prudent to check.
</p><p>
If all the relevant entries on the host are correct, let your
system administrator check the DNS server configuration for the
correct zone information. <span>For detailed
information about DNS, refer to
Chapter <i>The Domain Name System</i> (↑Reference).</span> If you have made sure that
the DNS configuration of your host and the DNS server are correct,
proceed with checking the configuration of your network and
network device.
</p></dd></dl></div></li><li><p>
If your system cannot establish a connection to a network server and
you have excluded name service problems from the list of possible
culprits, check the configuration of your network card.
</p><p>
Use the command <span class="command"><strong>ifconfig
<em class="replaceable"><code>network_device</code></em></strong></span> (executed as
<code class="systemitem">root</code>) to check whether this
device was properly configured. Make sure that both <code class="option">inet
address</code> and <code class="option">Mask</code> are configured correctly.
An error in the IP address or a missing bit in your network mask
would render your network configuration unusable. If necessary,
perform this check on the server as well.
</p></li><li><p>
If the name service and network hardware are properly configured and
running, but some external network connections still get long
time-outs or fail entirely, use <span class="command"><strong>traceroute
<em class="replaceable"><code>fully_qualified_domain_name</code></em></strong></span>
(executed as <code class="systemitem">root</code>) to track
the network route these requests are taking. This command lists any
gateway (hop) that a request from your machine passes on its way to
its destination. It lists the response time of each hop and whether
this hop is reachable at all. Use a combination of traceroute and
ping to track down the culprit and let the administrators know.
</p></li></ol></li></ol></div><p>
Once you have identified the cause of your network trouble, you can
resolve it yourself (if the problem is located on your machine) or let
the system administrators of your network know about your findings so
they can reconfigure the services or repair the necessary systems.
</p><div class="sect2" title="9.5.1. NetworkManager Problems"><div class="titlepage"><div><div><h3 class="title"><a name="sec.trouble.networkmanager"></a>9.5.1. NetworkManager Problems<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.networkmanager">¶</a></span></h3></div></div></div><p>
If you have a problem with network connectivity, narrow it down as
described in <a class="xref" href="cha.trouble.html#proc.trouble.config.net" title="Procedure 9.6. How to Identify Network Problems">Procedure 9.6, “How to Identify Network Problems”</a>. If NetworkManager seems to
be the culprit, proceed as follows to get logs providing hints on why
NetworkManager fails:
</p><div class="procedure"><ol class="procedure" type="1"><li><p>
Open a shell and log in as
<code class="systemitem">root</code>.
</p></li><li><p>
Restart the NetworkManager:
</p><pre class="screen">rcnetwork restart -o nm</pre></li><li><p>
Open a web page, for example, <a class="ulink" href="http://www.opensuse.org" target="_top">http://www.opensuse.org</a>
as normal user to see, if you can connect.
</p></li><li><p>
Collect any information about the state of NetworkManager in
<code class="filename">/var/log/NetworkManager</code>.
</p></li></ol></div><p>
For more information about NetworkManager, refer to
<a class="xref" href="cha.nm.html" title="Chapter 5. Using NetworkManager">Chapter 5, <i>Using NetworkManager</i></a>.
</p></div></div><div class="sect1" title="9.6. Data Problems"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="sec.trouble.data"></a>9.6. Data Problems<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.data">¶</a></span></h2></div></div></div><p>
Data problems are when the machine may or may not boot properly but, in
either case, it is clear that there is data corruption on the system and
that the system needs to be recovered. These situations call for a backup
of your critical data, enabling you to recover the system state from
before your system failed. openSUSE offers dedicated YaST modules
for system backup and restoration as well as a rescue system that can be
used to recover a corrupted system from the outside.
</p><div class="sect2" title="9.6.1. Managing Partition Images"><div class="titlepage"><div><div><h3 class="title"><a name="sec.trouble.data.partitions"></a>9.6.1. Managing Partition Images<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.data.partitions">¶</a></span></h3></div></div></div><p>
Sometimes you need to perform a backup from an entire partition or even
hard disk. Linux comes with the <span class="command"><strong>dd</strong></span> tool which can
create a exact copy of your disc. Combined with <span class="command"><strong>gzip</strong></span>
you save some space.
</p><div class="procedure" title="Procedure 9.7. Backing and Restoring up Harddiscs"><a name="id372860"></a><p class="title"><b>Procedure 9.7. Backing and Restoring up Harddiscs</b></p><ol class="procedure" type="1"><li><p>
Start a Shell as user <code class="systemitem">root</code>.
</p></li><li><p>
Select your source device. Typically this is something like
<code class="filename">/dev/sda</code> (labeled as
<em class="replaceable"><code>SOURCE</code></em>).
</p></li><li><p>
Decide where you want to store your image (labeled as
<em class="replaceable"><code>BACKUP_PATH</code></em>). It must be different from
your source device. In other words: if you make a backup from
<code class="filename">/dev/sda</code>, your image file must not be stored
under <code class="filename">/dev/sda</code>.
</p></li><li><p>
Run the commands to create a compressed image file:
</p><pre class="screen">dd if=/dev/<em class="replaceable"><code>SOURCE</code></em> | gzip > /<em class="replaceable"><code>BACKUP_PATH</code></em>/image.gz </pre></li><li><p>
Restore the hard disk with the following commands:
</p><pre class="screen">gzip -dc /<em class="replaceable"><code>BACKUP_PATH</code></em>/image.gz | dd of=/dev/<em class="replaceable"><code>SOURCE</code></em></pre></li></ol></div><p>
If you only need a partition to backup, replace the
<em class="replaceable"><code>SOURCE</code></em> placeholder with your respective
partition. In this case, your image file can lie on the same hard disk,
but on a different partition.
</p></div><div class="sect2" title="9.6.2. Backing Up Critical Data"><div class="titlepage"><div><div><h3 class="title"><a name="sec.trouble.data.backup"></a>9.6.2. Backing Up Critical Data<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.data.backup">¶</a></span></h3></div></div></div><div class="procedure"><a name="proc.trouble.data.backup"></a><p>
System backups can be easily managed using the YaST System Backup
module:
</p><ol class="procedure" type="1"><li><p>
As <code class="systemitem">root</code>, start YaST and select <span class="guimenu">System</span>+<span class="guimenu">System Backup</span>.
</p></li><li><p>
Create a backup profile holding all details needed for the backup,
filename of the archive file, scope, and type of the backup:
</p><ol type="a" class="substeps"><li><p>
Select <span class="guimenu">Profile Management</span>+<span class="guimenu">Add</span>.
</p></li><li><p>
Enter a name for the archive.
</p></li><li><p>
Enter the path to the location of the backup if you want to keep a
local backup. For your backup to be archived on a network server
(via NFS), enter the IP address or name of the server and the
directory that should hold your archive.
</p></li><li><p>
Determine the archive type and click <span class="guimenu">Next</span>.
</p></li><li><p>
Determine the backup options to use, such as whether files not
belonging to any package should be backed up and whether a list of
files should be displayed prior to creating the archive. Also
determine whether changed files should be identified using the
time-consuming MD5 mechanism.
</p><p>
Use <span class="guimenu">Expert</span> to enter a dialog for the backup of
entire hard disk areas. Currently, this option only applies to the
Ext2 file system.
</p></li><li><p>
Finally, set the search constraints to exclude certain system areas
from the backup area that do not need to be backed up, such as lock
files or cache files. Add, edit, or delete items until your needs
are met and leave with <span class="guimenu">OK</span>.
</p></li></ol></li><li><p>
Once you have finished the profile settings, you can start the backup
right away with <span class="guimenu">Create Backup</span> or configure
automatic backup. It is also possible to create other profiles
tailored for various other purposes.
</p></li></ol></div><div class="procedure"><a name="proc.trouble.data.profile"></a><p>
To configure automatic backup for a given profile, proceed as follows:
</p><ol class="procedure" type="1"><li><p>
Select <span class="guimenu">Automatic Backup</span> from the <span class="guimenu">Profile
Management</span> menu.
</p></li><li><p>
Select <span class="guimenu">Start Backup Automatically</span>.
</p></li><li><p>
Determine the backup frequency. Choose <span class="guimenu">daily</span>,
<span class="guimenu">weekly</span>, or <span class="guimenu">monthly</span>.
</p></li><li><p>
Determine the backup start time. These settings depend on the backup
frequency selected.
</p></li><li><p>
Decide whether to keep old backups and how many should be kept. To
receive an automatically generated status message of the backup
process, check <span class="guimenu">Send Summary Mail to User root</span>.
</p></li><li><p>
Click <span class="guimenu">OK</span> to apply your settings and have the first
backup start at the time specified.
</p></li></ol></div></div><div class="sect2" title="9.6.3. Restoring a System Backup"><div class="titlepage"><div><div><h3 class="title"><a name="sec.trouble.data.replay"></a>9.6.3. Restoring a System Backup<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.data.replay">¶</a></span></h3></div></div></div><p>
Use the YaST System Restoration module to restore the system
configuration from a backup. Restore the entire backup or select
specific components that were corrupted and need to be reset to their
old state.
</p><div class="procedure"><a name="proc.trouble.data.replay"></a><ol class="procedure" type="1"><li><p>
Start <span class="guimenu">YaST</span>+<span class="guimenu">System</span>+<span class="guimenu">System Restoration</span>.
</p></li><li><p>
Enter the location of the backup file. This could be a local file, a
network mounted file, or a file on a removable device, such as a
floppy or a DVD. Then click <span class="guimenu">Next</span>.
</p><p>
The following dialog displays a summary of the archive properties,
such as the filename, date of creation, type of backup, and optional
comments.
</p></li><li><p>
Review the archived content by clicking <span class="guimenu">Archive
Content</span>. Clicking <span class="guimenu">OK</span> returns you to the
<span class="guimenu">Archive Properties</span> dialog.
</p></li><li><p>
<span class="guimenu">Expert Options</span> opens a dialog in which to fine-tune
the restore process. Return to the <span class="guimenu">Archive
Properties</span> dialog by clicking <span class="guimenu">OK</span>.
</p></li><li><p>
Click <span class="guimenu">Next</span> to open the view of packages to restore.
Press <span class="guimenu">Accept</span> to restore all files in the archive or
use the various <span class="guimenu">Select All</span>, <span class="guimenu">Deselect
All</span>, and <span class="guimenu">Select Files</span> buttons to
fine-tune your selection. Only use the <span class="guimenu">Restore RPM
Database</span> option if the RPM database is corrupted or deleted
and this file is included in the backup.
</p></li><li><p>
After you click <span class="guimenu">Accept</span>, the backup is restored.
Click <span class="guimenu">Finish</span> to leave the module after the restore
process is completed.
</p></li></ol></div></div><div class="sect2" title="9.6.4. Recovering a Corrupted System"><div class="titlepage"><div><div><h3 class="title"><a name="sec.trouble.data.recover"></a>9.6.4. Recovering a Corrupted System<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.data.recover">¶</a></span></h3></div></div></div><a class="indexterm" name="id373437"></a><p>
There are several reasons why a system could fail to come up and run
properly. A corrupted file system following a system crash, corrupted
configuration files, or a corrupted boot loader configuration are the most
common ones.
</p><div class="sect3" title="9.6.4.1. Using the Rescue System"><div class="titlepage"><div><div><h4 class="title"><a name="sec.trouble.data.recover.rescue"></a>9.6.4.1. Using the Rescue System<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.data.recover.rescue">¶</a></span></h4></div></div></div><a class="indexterm" name="id373458"></a><a class="indexterm" name="id373463"></a><p>
openSUSE contains a rescue system. The rescue system is a small
Linux system that can be loaded into a RAM disk and mounted as root file
system, allowing you to access your Linux partitions from the outside.
Using the rescue system, you can recover or modify any important aspect
of your system:
</p><div class="itemizedlist"><ul class="itemizedlist" type="bullet"><li class="listitem" style="list-style-type: disc"><p>
Manipulate any type of configuration file.
</p></li><li class="listitem" style="list-style-type: disc"><p>
Check the file system for defects and start automatic repair processes.
</p></li><li class="listitem" style="list-style-type: disc"><p>
Access the installed system in a <span class="quote">“<span class="quote">change root</span>”</span>
environment.
</p></li><li class="listitem" style="list-style-type: disc"><p>
Check, modify, and reinstall the boot loader configuration.
</p></li><li class="listitem" style="list-style-type: disc"><p>
Resize partitions using the parted command. Find more information about
this tool at the GNU Parted website
<a class="ulink" href="http://www.gnu.org/software/parted/parted.html" target="_top">http://www.gnu.org/software/parted/parted.html</a>.
</p></li></ul></div><p>
The rescue system can be loaded from various sources and locations. The
simplest option is to boot the rescue system from the original
installation medium:
</p><div class="procedure"><a class="indexterm" name="id373544"></a><ol class="procedure" type="1"><li><p>
Insert the installation medium into your DVD drive.
</p></li><li><p>
Reboot the system.
</p></li><li><p>
At the boot screen, press <span class="keycap">F4</span> and choose
<span class="guimenu">DVD-ROM</span>. Then choose <span class="guimenu">Rescue
System</span> from the main menu.
</p></li><li><p>
Enter <code class="literal">root</code> at the <code class="literal">Rescue:</code> prompt.
A password is not required.
</p></li></ol></div><div class="procedure"><a name="proc.trouble.data.recover.rescue.network"></a><a class="indexterm" name="id373619"></a><p>
If your hardware setup does not include a DVD drive, you can boot the
rescue system from a network source<span> (including the
openSUSE FTP server)</span>. The following example applies to a
remote boot scenario—if using another boot medium, such as a DVD,
modify the <code class="filename">info</code> file accordingly and boot as you
would for a normal installation.
</p><ol class="procedure" type="1"><li><p>
Enter the configuration of your PXE boot setup and add the lines
<code class="literal">install=<em class="replaceable"><code>protocol</code></em>://<em class="replaceable"><code>instsource</code></em></code>
and <code class="literal">rescue=1</code>. If you need to start the repair
system, use <code class="literal">repair=1</code> instead. As with a normal
installation, <em class="replaceable"><code>protocol</code></em> stands for any of the
supported network protocols (NFS, HTTP, FTP, etc.) and
<em class="replaceable"><code>instsource</code></em> for the path to your network
installation source.
</p></li><li><p>
Boot the system using <span class="quote">“<span class="quote">Wake on LAN</span>”</span>, as described in
Section “Wake on LAN” (Chapter 1, <i>Remote Installation</i>, ↑Reference).
</p></li><li><p>
Enter <code class="literal">root</code> at the <code class="literal">Rescue:</code> prompt.
A password is not required.
</p></li></ol></div><p>
Once you have entered the rescue system, you can make use of the virtual
consoles that can be reached with
<span class="keycap">Alt</span>+<span class="keycap">F1</span> to
<span class="keycap">Alt</span>+<span class="keycap">F6</span>.
</p><p>
A shell and many other useful utilities, such as the mount program, are
available in the <code class="filename">/bin</code> directory. The
<code class="filename">sbin</code> directory contains important file and network
utilities for reviewing and repairing the file system. This directory
also contains the most important binaries for system maintenance, such as
fdisk, mkfs, mkswap, mount, mount, init, and shutdown, and ifconfig, ip,
route, and netstat for maintaining the network. The directory
<code class="filename">/usr/bin</code> contains the vi editor, find, less, and
ssh.
</p><p>
To see the system messages, either use the command
<span class="command"><strong>dmesg</strong></span> or view the file
<code class="filename">/var/log/messages</code>.
</p><div class="sect4" title="9.6.4.1.1. Checking and Manipulating Configuration Files"><div class="titlepage"><div><div><h5 class="title"><a name="sec.trouble.data.recover.rescue.file"></a>9.6.4.1.1. Checking and Manipulating Configuration Files<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.data.recover.rescue.file">¶</a></span></h5></div></div></div><p>
As an example for a configuration that might be fixed using the rescue
system, imagine you have a broken configuration file that prevents the
system from booting properly. You can fix this using the rescue system.
</p><div class="procedure"><p>
To manipulate a configuration file, proceed as follows:
</p><ol class="procedure" type="1"><li><p>
Start the rescue system using one of the methods described above.
</p></li><li><p>
To mount a root file system located under
<code class="filename">/dev/sda6</code> to the rescue system, use the following
command:
</p><pre class="screen">mount /dev/sda6 /mnt</pre><p>
All directories of the system are now located under
<code class="filename">/mnt</code>
</p></li><li><p>
Change the directory to the mounted root file system:
</p><pre class="screen">cd /mnt</pre></li><li><p>
Open the problematic configuration file in the vi editor. Adjust and
save the configuration.
</p></li><li><p>
Unmount the root file system from the rescue system:
</p><pre class="screen">umount /mnt</pre></li><li><p>
Reboot the machine.
</p></li></ol></div></div><div class="sect4" title="9.6.4.1.2. Repairing and Checking File Systems"><div class="titlepage"><div><div><h5 class="title"><a name="sec.trouble.data.recover.rescue.filesystem"></a>9.6.4.1.2. Repairing and Checking File Systems<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.data.recover.rescue.filesystem">¶</a></span></h5></div></div></div><a class="indexterm" name="id373887"></a><p>
Generally, file systems cannot be repaired on a running system. If you
encounter serious problems, you may not even be able to mount your root
file system and the system boot may end with a <span class="quote">“<span class="quote">kernel
panic</span>”</span>. In this case, the only way is to repair the system from
the outside. <span>The rescue system provides all tools
needed for a manual file system check or repair.</span> It contains the
utilities to check and repair the <code class="literal">ext2</code>,
<code class="literal">ext3</code>, <code class="literal">ext4</code>,
<code class="literal">reiserfs</code>, <code class="literal">xfs</code>,
<code class="literal">dosfs</code>, and <code class="literal">vfat</code> file systems.
</p></div><div class="sect4" title="9.6.4.1.3. Accessing the Installed System"><div class="titlepage"><div><div><h5 class="title"><a name="sec.trouble.data.recover.rescue.access"></a>9.6.4.1.3. Accessing the Installed System<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.data.recover.rescue.access">¶</a></span></h5></div></div></div><p>
If you need to access the installed system from the rescue system to,
you need to do this in a <span class="emphasis"><em>change root</em></span> environment.
For example, to modify the boot loader configuration, or to execute a
hardware configuration utility.
</p><p>
To set up a change root environment based on the installed system,
proceed as follows:
</p><div class="procedure"><ol class="procedure" type="1"><li><p>
First mount the root partition from the installed system and the
device file system (change the device name to your current settings):
</p><pre class="screen">mount /dev/sda6 /mnt
mount --bind /dev /mnt/dev</pre></li><li><p>
Now you can <span class="quote">“<span class="quote">change root</span>”</span> into the new environment:
</p><pre class="screen">chroot /mnt</pre></li><li><p>
Then mount <code class="filename">/proc</code> and <code class="filename">/sys</code>:
</p><pre class="screen">mount /proc
mount /sys</pre></li><li><p>
Finally, mount the remaining partitions from the installed system:
</p><pre class="screen">mount -a</pre></li><li><p>
Now you have access to the installed system. Before rebooting the
system, unmount the partitions with <span class="command"><strong>umount
<code class="option">-a</code></strong></span> and leave the <span class="quote">“<span class="quote">change root</span>”</span>
environment with <span class="command"><strong>exit</strong></span>.
</p></li></ol></div><div class="warning"><table border="0" cellpadding="3" cellspacing="0" width="100%" summary="Warning: Limitations"><tr class="head"><td width="32"><img alt="[Warning]" src="admon/warning.png"></td><th align="left">Limitations</th></tr><tr><td colspan="2" align="left" valign="top"><p>
Although you have full access to the files and applications of the
installed system, there are some limitations. The kernel that is
running is the one that was booted with the rescue system, not with the
change root environment. It only supports essential hardware and it is
not possible to add kernel modules from the installed system unless the
kernel versions are exactly the same (which is unlikely). So you cannot
access a sound card, for example. It is also not possible to start a
graphical user interface.
</p><p>
Also note that you leave the <span class="quote">“<span class="quote">change root</span>”</span> environment
when you switch the console with
<span class="keycap">Alt</span>+<span class="keycap">F1</span> to
<span class="keycap">Alt</span>+<span class="keycap">F6</span>.
</p></td></tr></table></div></div><div class="sect4" title="9.6.4.1.4. Modifying and Reinstalling the Boot Loader"><div class="titlepage"><div><div><h5 class="title"><a name="sec.trouble.data.recover.rescue.grub"></a>9.6.4.1.4. Modifying and Reinstalling the Boot Loader<span class="permalink"><a alt="Permalink" title="Copy Permalink" href="#sec.trouble.data.recover.rescue.grub">¶</a></span></h5></div></div></div><p>
Sometimes a system cannot boot because the boot loader configuration is
corrupted. The start-up routines cannot, for example, translate physical
drives to the actual locations in the Linux file system without a
working boot loader.
</p><p>
To check the boot loader configuration and reinstall the boot loader,
proceed as follows:
</p><div class="procedure"><ol class="procedure" type="1"><li><p>
Perform the necessary steps to access the installed system as
described in <a class="xref" href="cha.trouble.html#sec.trouble.data.recover.rescue.access" title="9.6.4.1.3. Accessing the Installed System">Section 9.6.4.1.3, “Accessing the Installed System”</a>.
</p></li><li><p>
Check whether the following files are correctly configured according
to the GRUB configuration principles outlined in
Chapter <i>The Boot Loader GRUB</i> (↑Reference) and apply fixes if necessary.
</p><div class="itemizedlist"><ul class="itemizedlist" type="bullet"><li class="listitem" style="list-style-type: disc"><p>
<code class="filename">/etc/grub.conf</code>
</p></li><li class="listitem" style="list-style-type: disc"><p>
<code class="filename">/boot/grub/device.map</code>
</p></li><li class="listitem" style="list-style-type: disc"><p>
<code class="filename">/boot/grub/menu.lst</code>
</p></li><li class="listitem" style="list-style-type: disc"><p>
<code class="filename">/etc/sysconfig/bootloader</code>
</p></li></ul></div></li><li><p>
Reinstall the boot loader using the following command sequence:
</p><pre class="screen">grub --batch < /etc/grub.conf</pre></li><li><p>
Unmount the partitions, log out from the <span class="quote">“<span class="quote">change root</span>”</span>
environment, and reboot the system:
</p><pre class="screen">umount -a
exit
reboot</pre></li></ol></div></div></div></div></div></div><div class="navfooter"><table width="100%" summary="Navigation footer" border="0" class="bctable"><tr><td width="80%"><div class="breadcrumbs"><p><a href="index.html"> Documentation</a><span class="breadcrumbs-sep"> > </span><a href="book.opensuse.startup.html">Start-Up</a><span class="breadcrumbs-sep"> > </span><a href="part.trouble.html">Help and Troubleshooting</a><span class="breadcrumbs-sep"> > </span><strong><a accesskey="p" title="Chapter 8. Help and Documentation" href="cha.userhelp.html"><span>◀</span></a> </strong></p></div></td></tr></table></div></body></html>
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