This article basically address the problem when X Window won’t start after you have installed VirtualBox Guest Addition in Fedora as Guest OS.
If you are using the latest version of VirtualBox and Fedora 12, you should not have any problem with the drivers. The VBox video drivers works well with HAL in Fedora.
However, there is one exception. After installing VirtualBox Guest Addition on Fedora, you can freely adjust the size of the windows in the VirtualBox. If you happen to adjust VirtualBox windows to maximize the full screen on a 22″ or greater LCD, you will have problem starting X Windows on the next reboot. After maximizing the VirtualBox to the maximum, you would not be able to start X Window (specifically gdm) on the next reboot.
I have a 22″ LCD monitor with default resolution of 1680×1050 in Windows Vista. I have manage to adjust the VirtualBox Window (Fedora 12 as Guest) to 1504×932 without problem restarting Fedora. However, if I maximize the VirtualBox Window to occupy the full screen except Vista status bar (resolution of 1680×957), I would have problem starting X Window on the next reboot.
There are 2 ways to resolve this issue.
The first solution is NOT to maximize the VirtualBox window before restarting Fedora. If you need to maximize the VirtualBox window to work on Fedora, you must remember to reduce the window back to its original size. This is the easiest solution except that you have to remember to reduce the window before restarting Fedora or shutting down Fedora.
If you prefer to work on the maximize VirtualBox window size all the time, you can do so that by reverting to the old method of configuring the screen resolution using configuration file. The second solution is to manually configure screen resolution. Please be aware that after configuring the screen resolution, you cannot adjust VirtualBox window freely anymore.
We use xorg.conf configuration file to configure screen resolution. This file is no longer located at /etc/X11 because Fedora is using HAL to manage video and screen resolution. In the older Fedora system, xorg.conf is the main configuration file for video size, dept and resolution.
How to Login when X Windows Fails to Start
When X Windows fails to start, use the key Ctrl+Fn+F2 or Ctrl+Fn+F3 to switch to another virtual windows using console login.
Creating X11 Video Configuration File (xorg.conf)
Since the new Fedora system don’t use xorg.conf anymore. You couldn’t find it in /etc/X11 folder. To generate this file automatically use the command #Xorg -configure. This command creates a file “xorg.conf.new” after probing the video system. You need to read the output as it indicates where this new file is created.
Then you need to rename the file to xorg.conf and move this configuration file to /etc/X11 folder.
Finally, you need to define the screen resolution in the configuration file.
Amending the Configuration File
Open the file xorg.conf with your favorite editor.
On the section “Screen”, look for subsection “Display” with depth of 24.
Insert a new line indicating the Modes “1680×957”, as follows:
Identifier “Default Screen”
Monitor “Configured Monitor”
Device “Configured Video Device”
The resolution of 1680×957 is the maximize window size excluding the Windows task bar. If you have different screen resolution, please check the most appropriate resolution for your screen.
Please note that using the xorg.conf will prevents you from adjusting the VirtualBox window dynamically.
If you want to revert to dynamic window adjustment, make sure Fedora is shut down with smaller screen resolution. You can remove the file xorg.conf.