Changing Video Resolutions on a Host Machine Running Linux

Situation

Explanation

A virtual machine runs at a resolution that does not match a mode supported by XFree86.

The VidMode extension can choose only resolutions that are already configured in the XF86Config file on the host machine. If a virtual machine runs at a resolution that does not match a known mode, then VMware GSX Server tries to choose the closest larger mode, or else it simply does not switch display resolutions at all.

Modes are configured in the XF86Config file that your monitor does not support.

If your XFree86 configuration was automatically generated, it is possible that some enabled modes might not actually work with your monitor. However, the VidMode code in VMware GSX Server has no way of knowing this and a virtual machine that attempts to use a resolution that is not supported by your monitor may cause your display to either look distorted or fail to display.

If this happens, immediately leave full screen mode. Then either disable the mode switching feature in VMware GSX Server or else fix your XFree86 configuration and restart X.

However, if the only problem is that the image is off center or is not quite the right size on the monitor, then it can almost certainly be corrected without problem using the monitor controls. Note that most modern monitors are capable of keeping separate settings for each resolution, so changing the settings for a new mode should not impair the settings for the host resolution.

The mouse completely fails to move while in a full screen mode virtual machine.

XFree86 version 3.3.3.0 (not in any mainstream Linux distribution) broke the DirectMouse interface. The interface works correctly in all previous and subsequent releases of XFree86.

If you have an X server based on XFree86 version 3.3.3.0, then you may find yourself unable to move the mouse while in full screen mode with the VidMode extension enabled. The problem goes away if you either disable video resolution switching in VMware GSX Server or update your X server.

To disable video resolution switching in VMware GSX Server, select Settings > Configuration Editor, then deselect Find best resolution under the Misc panel.