Virtual Desktop Size in RHEL5 Beta 1

I had trouble getting the virtual screen size in RHEL5 Beta 1 to match my monitor's native resolution. It is an HP L1706 attached to a dc5100 SFF.

RHEL defaulted to 1600x1280 (or so) and the LCD's native resolution is 1280x1024 @ 60Hz. This resulted in the display panning around the virtual desktop when the mouse reached a screen edge. It also caused the menu and task bars to not always be available on screen, since they were at the edges of the virtual desktop.

Unfortunately the settings from System-->Administration-->Display, system-config-display, did not correct this. X reverted to the larger size.

I tried to use

system-config-display --set-resolution 1280 1024

This sets the Virtual setting, but /var/log/Xorg.0.log told me there was no matching mode. Well, system-config-display has no command line switch for setting the mode(s).

So, I manually edited /etc/X11/xorg.conf to contain:

SubSection "Display"
       Virtual   1280 1024
       Modes "1280x1024x60"
EndSubSection

in the Screen section.

This produced the desired effect, running the monitor at its recommended settings and setting the virtual desktop size to match it.