Red Hat Linux Bible: Fedora and Enterprise Edition
Graphical Administrative Interfaces
To help you simplify Linux administration, several graphical administrative
utilities are now available. These interfaces attempt to organize the
information that you need to get a whole job done in one place. The interface
handles placing the information that you enter into the correct configuration
files and setting up the correct commands to run.
Graphical interfaces are a step in the right direction toward making Linux
useable by the general population. The problem is, however, that these
don’t yet enable you to do everything that you need to do, so you
often find yourself needing to edit a configuration file by hand after
you enter the information into that file using a graphical application.
You will find that you need to do this less for simple tasks (such as
adding a user account) than you will for more complex tasks (such as configuring
Another downside of graphical administrative interfaces in Linux is that
they tend to cause versions of Linux to diverge. The configuration files
created as you set up a dial-out Internet connection by using PPP with
the Network configuration in Red Hat Linux, for example, are different
from the files that you would create setting up PPP on a different version
of Linux. This can make to getting information on your particular situation
a bit difficult.
The following sections describe the major graphical interfaces used for
administration in Red Hat Linux.
The most complete graphical utility for working with Red Hat Linux is
linuxconf. As a GUI interface, linuxconf isn’t fancy. Don’t
expect to see lots of icons or to drag and drop items on the display.
It does, however, offer several significant advantages over just editing
configuration files directly:
- Configuration and control tools for many different features are
all contained in one place. Just click an activity in the left column
and a form for configuring the item appears in the right column. You don’t
need to search blindly in etc for the right files to edit.
- Some error checking is done. In many cases, linuxconf prevents
you from entering invalid values in the fields.
- Options are offered. If, for example, you are adding a network
interface, you can click a menu to select from the interfaces that Linux
knows about (such as PPP or Ethernet).
Administrative activities are divided into three major categories in linuxconf:
Config, Control, and Status. Config activities enable you to set up your
network interfaces (for both client and server features), work with user
accounts, configure file systems, and manage how Linux boots. Control
activities enable you to work with features that are already configured,
including starting and stopping services, mounting/unmounting file systems,
and controlling the files and systems used by linuxconf. Status activities
enable you to view system logs.
You can start linuxconf from a terminal window (linuxconf
&). Figure 1 shows the Linuxconf window.
Figure 1: Linuxconf centralizes Linux administration in one graphical
|TIP: Linixconf can also be operated from Netscape
or another Web browser from any computer that can reach your system
from the network. To do that, the remote computer would simply request
port number 98 from your computer. If your computer were named comp1,
for example, you could start linuxconf by typing the Web address:
http://comp1:98/. (You may need to activate
the linuxconf service for this to work.)
To choose a task to perform in linuxconf, click the task in the left column.
A form representing the task appears on the right. Select the options
that you want and fill in the necessary information. Accept the changes
by clicking Accept or OK. Click Cancel after you are done. You can also
use the following function keys and control keys with linuxconf:
- Ctrl+X — If the current field contains a pop-up selection list (indicated by a down arrow), this key opens the list.
- F3 — Escapes from any dialog box.
- Ctrl+A — Goes to the beginning of the line.
- Ctrl+B — Goes up one page.
- Ctrl+D — Deletes the current character.
- Ctrl+E — Goes to the end of the line.
- Ctrl+F — Goes down one page.
- Ctrl+K — Deletes text to the end of the line.
Linuxconf configuration tasks
Under the configuration section in linuxconf are tasks for setting up
your network, creating user accounts, working with file systems, initializing
system services, and choosing boot modes. Networking tasks are divided
into those that apply to your computer as a client and those that apply
to it as a server.
Linuxconf networking tasks
Client networking tasks enable you to view and configure information
associated with your computer’s host name, the network interfaces
that are attached to your computer, and the routes that you can use to
get to other hosts and networks. Click the plus sign (+)
next to Client tasks and select Basic host information. From the window
that appears, here are some of the items that you can change:
- Host name — Your host name is how other computers
on the network identify yours. It can contain the full hostname.domainname
- Adaptor — The network interfaces (that is,
Ethernet cards, PPP dial-up connections, and so on) that give you access
to the network can be viewed by clicking the Adaptor tabs on the Basic
host information form. The information that you would need to enter
in this form is described in detail in Chapter 15, "Setting Up
a Local Area Network."
Your system resolves Internet host names into IP addresses by identifying
DNS servers that can perform name-to-address resolution. Click the Name
Server Specification (DNS) task to add your default domain and one or
more name servers. You can also indicate in which domains to search for
Under Routing and Gateways, you can define how your networking requests
are routed across gateway machines (those that are connected to your subnetwork
and another subnetwork) to reach beyond your local network. You can also
specify routes to other local area networks.
Other network services that you can configure include the Network Information
Service (NIS), IPX interface, and serial IP connections (PPP, SLIP, and
PLIP). NIS is a way of having a central server store the information that
each client computer needs to start up. IPX is a networking interface
protocol that is popular with NetWare servers, and PPP, SLIP, and PLIP
are ways to connect by using Internet protocols across modems, direct
connections, and other serial lines.
If you make any changes to your network configuration, you can activate
those changes by clicking the Act/Changes button. You can either preview
what needs to be done to activate the changes or click Activate the Changes
for the changes to be implemented and the network to be restarted.
Under Server tasks, you can share your file systems with other computers
on the network (by using NFS) and set up IP aliases for virtual hosts.
You also find tasks for configuring a mail server and an Apache Web Server.
Other Linuxconf configuration tasks
Besides networking tasks, you can select from several other basic system
tasks in linuxconf. Under User Accounts, you can add normal user accounts,
special user accounts, e-mail aliases, and policies regarding user accounts.
Under File Systems, you can add definitions of mountable local drives
or NFS file systems (from remote systems) that can later be added to or
removed from your system (by using mount and unmount tasks described in
the Control section). Finally, you can add parameters that affect how
your Linux system boots.
Linuxconf control tasks
The Control section of linuxconf enables you to work with Linux features
that change the on-going operation of your Red Hat Linux system. Here
are some of the tasks that you can do from this section:
- Activate configuration — For changes that you
make to take effect, some services must be stopped and restarted. This
task checks what needs to be restarted, based on the changes that you
have made, and then restarts those services after you say that you are
- Shutdown/reboot — Use this task to either shut
down and halt your computer or reboot it.
- Control service activity — You can enable or
disable a variety of network services by selecting this task.
- Mount/Unmount file systems — Any local or NFS
file systems that you configured to be mountable (in the Configuration
section) can be mounted or unmounted by using these tasks.
- Configure superuser schedule — You can add
commands that are run at a set schedule (by using the cron facility)
as the root user by adding entries under this task.
- Archive configurations — With this task, you
can archive the configuration files that you have set up so that you
can recall these saved configuration files later. This task can be used
to get you back to a sane state if your configuration files get wrecked.
- Switch system profile — You can recall a past
archive of configuration files (and save the current configuration files)
by using this task.
- Control files and systems — Select tasks from
this section to change the way that configuration files, commands, file
permissions, modules, system profiles, and linuxconf add-ons are configured
and used in linuxconf.
- Date & time— Change the date, time, and
time zone from this task.
- Features — Modify the keyboard mapping used
for your Linux computer, the language, or several features associated
with how HTML is used on your computer.
After you have made changes to any configurations that require programs
to be restarted, you can click Act/Changes. Then click the Activate the
Changes button that appears. If errors are reported, click Yes to view
those messages. Then you can view the log that was created from the changes.
Linuxconf subsection commands
Instead of using linuxconf, you can use commands to go directly to particular
configuration sections. commands:
- Filesystem configurator— Configures the file
systems that your computer can access. This can include local drives
and NFS volumes (mounted from remote computers). It also enables you
to configure swap files and partitions and set the quota Filesystem
configurator window (see Figure 2).
Figure 2: Mount local
and remote file systems by using the Filesystem configurator.
- Network configurator (netconf)
— Configures your TCP/IP network. It enables you to add everything
that you need to create connections to modems and Ethernet LANs. You
can set up the Domain Name System (DNS), routing and gateways, and serial
communications (PPP, SLIP, or PLIP). Figure 3 shows the Network configurator
Figure 3: Set up TCP/IP
network connections by using the Network configurator.
- User Account configurator (userconf) — Manages
your computer’s user accounts. It enables you to add regular user
and group definitions and then assign passwords to users. You can also
add special user accounts, such as those that enable you to automatically
log in and start a PPP, SLIP, UUCP, or POP connection. Figure 4 shows
the User account configurator window.
Figure 4: Add regular and special user accounts in the User
account configurator window.