The System Tools menu of the GNOME and KDE desktops provides access to a set of tools that help you administer Red Hat Linux. The distinction between these tools and the tools provided by the System Settings menu is rather arbitrary. That is, any given tool could as likely have been placed on one menu rather than the other. Generally, items on the System Tools menu perform an action, whereas items on the System Settings menu let you configure a facility. But, exceptions to this rule of thumb abound.
The tools provided by the System Tools menu are:
Provides access to the User Mount Tool, which lets users mount, unmount, and format filesystems
Provides access to the Format a Floppy tool, which formats floppies
Provides access to the Hardware Browser tool, which displays information about system hardware
Provides access to a wizard that assists you in creating new network connections
Provides access to the Kickstart Configurator tool, which lets you specify the parameters for automated installation of Red Hat Linux
Provides access to the Network Device Control tool, which lets you configure and administer network devices and connections
Provides access to the Red Hat Update Agent, which assists Red Hat Network subscribers in updating their systems
Provides access to the System Logs tool, which lets you view the contents of system log files
Provides access to the System Monitor tool, which lets you view system performance and resource consumption information
Provides access to a shell, which lets you enter commands
Provides access to the My Traceroute tool, which lets you determine the network distance to a specified host
This section describes several of the tools. However, it does not explain the Floppy Formatter, since that tool appears only on the GNOME menu and since its functions are also provided by the Disk Manager. Some of the tools are described elsewhere in this book. For instance, Chapter 8 explains the Red Hat Update Agent. The Network Device Control and Traceroute tools concern network configuration and administration, which are topics considered in Chapter 10 and Chapter 11. The Kickstart tool is primarily used by enterprise system administrators and is not described in this book. And, I dispense with explanation of the Terminal tool, since its use should be self-evident.
The Disk Management tool lets you mount and unmount filesystems. It also lets you format filesystems. To launch the tool, choose System Tools Disk Management from the GNOME or KDE menu. Figure 9-21 shows the tool.
The tool shows a list of configured filesystems, taken from /etc/fstab. To mount a filesystem, select the filesystem and click Mount. If you mount a floppy or CD-ROM under GNOME, an icon representing the mounted filesystem appears on the desktop. Click the icon to browse the filesystem.
To unmount a mounted filesystem, select the filesystem and click Unmount. The usual restrictions apply concerning the inability to unmount a file that is in use.
To format a filesystem, select the unmounted filesystem and click Format. A dialog box appears, as shown in Figure 9-22. The dialog box lets you choose the type of filesystem to create. For floppies, you may find it convenient to use the vfat file system, which can be read by Linux and Windows 9x, ME, 2000, and XP. For other purposes, you should generally use the standard Linux filesystem type, ext3. The dialog box also lets you choose whether a low-level format should be performed. Generally, you should perform a low-level format only when formatting a floppy.
The Hardware Browser tool lets you view information describing the system's hardware devices. To launch the tool, select System Tools Hardware Browser from the GNOME or KDE menu. Figure 9-23 shows the tool. When it starts up, the tool probes your system and may require a minute or so to complete its work. During that time, the system may become unresponsive.
To use the tool, click a device in the list at the left side of the window. A description of the device appears in the right side of the window. The tool does not let you change or configure devices. It merely lets you view information describing them.
The System Monitor tool lets you view information about system and user processes (running programs). It also lets you view CPU, memory, and disk space usage data. Essentially, the tool combines the functions performed under Windows by the Task Manager and System Information applets. To launch the tool, choose System Tools System Monitor from the GNOME or KDE menu. Figure 9-24 shows the tool.
The display uses a tree control that displays members of a process group under their parent processes. Click the triangle next to the name of a parent process to expand or collapse the tree. To view extended information about a process, select the process and click More Info. The bottom pane of the tool is changed to show information about the selected process, as shown in Figure 9-25.
You can terminate a process by selecting it and clicking End Process. However, you should do so only judiciously. Terminating a necessary process or terminating a process at an unsuitable time may destabilize your system. Generally, you should terminate only processes that appear to be hung.
If the list of processes is long, you may find it convenient to use the Search box. Or, you can use the View list to view all processes, processed owned by your user account, or active processes.
Clicking the System Monitor tab displays information like that shown in Figure 9-26. The tab includes graphs that provide a running display of CPU, memory, and swap space usage. In addition, the tab includes a list box that displays the used and total space associated with mounted disk partitions.
The System Logs tool lets you view information contained in system log files, which record information about important events. The tool is especially helpful in troubleshooting system problems, because log files may contain relevant entries that indicate or suggest the cause of the problem.
To launch the tool, choose System Tools System Logs from the GNOME or KDE menu. Figure 9-27 shows the tool. To view log entries, select the desired log file in the left part of the window. The log entries appear in the right part of the window. To find a particular entry or set of entries within a log file, type text into the textbox labeled "Filter for." The tool will then display only log entries containing the specified text. To disable the filter, click Reset.
The log files available for viewing depend on which packages are installed. The standard log files are:
Contains information about services started and stopped during system boot up and shutdown
Contains information about the cron service, which runs tasks at scheduled times
Contains information recorded during system boot up
Contains information about the mail server and mail messages
Contains information about the USENET news service
Contains information about package installations and removals
Contains information about logins and certain service start ups and shutdowns
Contains general-purpose entries not sent to another log and some important entries also sent elsewhere
Contains entries describing actions performed by the Red Hat Update Agent
Contains entries logged by the X server