Common Problems and Their Solutions

Contents

9.1. Finding and Gathering Information
9.2. Installation Problems
9.3. Boot Problems
9.4. Login Problems
9.5. X Window System Problems
9.6. Network Problems
9.7. Data Problems

This chapter offers a range of common problems that can arise with an intention of covering as many of the various types of potential problems as possible. That way, even if your precise situation is not listed here, there might be one similar enough to offer hints as to the solution.

Finding and Gathering Information

Linux logs things in a fair amount of detail. There are several places to look when you have problems with your system, most of which are standard to Linux systems in general and some of which are relevant to openSUSE systems. Most log files can also be viewed with YaST (Miscellaneous+Start-Up Log).

YaST offers the possibility to collect all system information needed by the support team. Use Miscellaneous+Support Query. Select the problem category. When all information is gathered, attach it to your support request.

The following is a list of the most commonly checked log files and what they typically contain.

Table 9.1. Log Files

Log File	Description
`~/.xsession-errors`	Messages from the desktop applications currently running. The `~` is the home directory of the current user.
`/var/log/apparmor/`	Log files from AppArmor, see Part “Confining Privileges with Novell AppArmor” (↑Security Guide) for detailed information.
`/var/log/audit/audit.log`	Log file from Audit to track any access to files, directories, or resources of your system and trace system calls.
`/var/log/boot.msg`	Messages from the kernel during the boot process.
`/var/log/mail.*`	Messages from the mail system.
`/var/log/messages`	Ongoing messages from the kernel and system log daemon when running.
`/var/log/NetworkManager`	Log file from NetworkManager to collect problems with network connectivity
`/var/log/samba/`	Directory containing Samba server and client log messages.
`/var/log/SaX.log`	Hardware messages from the SaX display and KVM system.
`/var/log/warn`	All messages from the kernel and system log daemon assigned WARNING level or higher.
`/var/log/wtmp`	Binary file containing user login records for the current machine session. View it with last.
`/var/log/Xorg.*.log`	Various start-up and runtime logs from the X Window system. It is useful for debugging failed X start-ups.
`/var/log/YaST2/`	Directory containing YaST's actions and their results.
`/var/log/zypper.log`	Log file of zypper.

Apart from log files, your machine also supplies you with information about the running system. See Table 9.2: System Information With the /proc File System

Table 9.2. System Information With the /proc File System

File	Description
`/proc/cpuinfo`	This displays processor information, including its type, make, model, and performance.
`/proc/dma`	This shows which DMA channels are currently being used.
`/proc/interrupts`	This shows which interrupts are in use and how many of each have been in use.
`/proc/iomem`	This displays the status of I/O (input/output) memory.
`/proc/ioports`	This shows which I/O ports are in use at the moment.
`/proc/meminfo`	This displays memory status.
`/proc/modules`	This displays the individual modules.
`/proc/mounts`	This displays devices currently mounted.
`/proc/partitions`	This shows the partitioning of all hard disks.
`/proc/version`	This displays the current version of Linux.

Apart from the /proc file system, the Linux kernel exports information with the sysfs module, an in-memory filesystem. This module represents kernel objects, their attributes and relationships. More about sysfs in the context of udev can be found in Chapter Dynamic Kernel Device Management with udev (↑Reference). Table 9.3 contains an overview of the most common directories under /sys.

Table 9.3. System Information With the /sys File System

File	Description
`/sys/block`	Contains subdirectories for each block device discovered from the system. Generally, these are mostly disk type devices.
`/sys/bus`	Contains subdirectories for each physical bus type
`/sys/class`	Contains subdirectories grouped together as a functional type of a device (like graphics, net, printer, etc.)
`/sys/device`	Contains the global device hierarchy.

Linux comes with a number of tools for system analysis and monitoring. See Chapter System Monitoring Utilities (↑Reference) for a selection of the most important ones used in system diagnostics.

Each scenario included in the following 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 might be related.