Switching Desktop Environments
Red Hat Linux 6 ships with several desktop environments—also called X-Window shells—besides Gnome. These desktop environments are actually programs written to run on top of the older, command-line Linux. They launch automatically when Linux starts. By and large, you won't know that Linux is running under the shell, any more than Microsoft Windows users know that DOS is running. In addition, with the release of Red Hat Linux 6, so many features are built into the Gnome desktop environment that you may not ever need to leave the graphical environment.
Gnome is the default desktop environment and the one that Red Hat Linux 6 automatically activates. It is also clearly an extremely rich and robust visual environment. However, you may want to explore the offerings of the other desktop environments that are installed with Red Hat Linux 6: the K Desktop Environment (KDE) and Another Level. You may also switch to another environment by mistake and then want to get back to Gnome. This section explains how to switch among desktop environments.
To switch desktops:
1. | Select the Desktop Switching tool from the System menu on the Gnome Main menu. The Desktop Switcher will open (Figure 3.25). |
2. | Select the desktop you want to switch to: for example, KDE. |
3. | If you want the change to become permanent—for example, if you want this desktop to appear each time you start Red Hat Linux 6—uncheck the Change Only Applies to Current Display check box. If you want to change the desktop for only the current session, put a check in the check box. |
4. | Click OK. Your desktop environment will change to reflect your choice. |
To switch back to Gnome:
1. | Log off of the current shell or reboot the computer. |
2. | |
3. | From the Session menu, select Gnome. |
4. | Log on normally. |
Tip
You can use the Desktop Switcher tool to make Gnome your default desktop environment, if this setting has been changed.
Figure 3.26. You can start up a desktop environment by clicking Options on the Red Hat logon screen and selecting the desktop environment from the Sessions menu.
Booting to the command line
Of course, there are those among us who do not like visual desktops. With Red Hat Linux 6, you can configure your system to simply boot to the command prompt.
To boot to the command prompt directly:
1. | Log on as root by typing root for the logon ID and the root password at the Red Hat Linux 6 log on screen; or open a terminal window, type su root at the command prompt, and enter the root password. |
2. | If you are logged on as root, select Con-trol Panel from the System menu on the Gnome Main menu; or in the open terminal window, type control-panel. The control panel will open (Figure 3.27). |
3. | Open the System Configuration applet by clicking the button that displays an orchestra conductor (fourth button from the left in Figure 3.27). The Gnome Linux Configuration applet will open (Figure 3.28). |
4. | Scroll down the list on the left side to Miscellaneous services. |
5. | Double-click Miscellaneous Services to expand the category. |
6. | |
7. | On the right side, change the initial default run level from run level 5 to run level 3. |
8. | Click the Accept button. |
9. | Click Save Changes. |
10. | Click Quit. |
11. | Reboot your computer. It will boot to the Linux command prompt. |
To start Gnome from the command prompt:
-
At the command prompt, type startx.
To restore booting to a visual environment:
-
Once you have started Gnome, follow the procedure outlined in "To boot to the command prompt directly." Set the initial default run level to run level 6.
Linux run levels
Linux run levels are used to determine what activities can or should be taking place. Here are some more specifics:
Run Level 0When the system enters this run level, the system shutdown sequence is initiated. This sequence includes killing all processes, turning off virtual memory, cleaning up swap files, and unmounting file systems.
Run level 1A single-user administrative state used for performing low-level maintenance. No one besides the administrator can log on or off.
Run level 2Simple multiuser state, with networking enabled but with the file system disabled.
Run level 3The default command-line run state, with all services, including remote file sharing, enabled.
Run level 4A user-configurable run level that, in theory, you can set up to selectively stop or start processes.
Run level 5The default run state in Red Hat Linux 6. All run level 3 services are enabled, with the addition of the X-window server.