Hello. I'd like to find a way to have a default screen resolution for GDM and new users that is smaller than the maximum allowed resolution accessible by xrandr, and I can't seem to find a way to do it. Here's what I've done:
I installed ubuntu hardy, and my CRT, which looks best at 1024x768 wound up displaying at 1600x1200. I can change my resolution using xrandr (gnome monitor resolution settings), but that doesn't affect GDM, or other new users on the system.
I tried setting the mode to 1024x768 in /etc/X11/xorg.conf, but that leaves xrandr with nothing bigger than 1024x768. I'd really like a user to be able to select a higher resolution if they choose, but still default to 1024x768.
So I tried various methods of adding higher modes, or adding a virtual line with higher resolution, but these all result in having a larger virtual screen size with only 1024x768 visible. The gdm login box winds up off-centered, or if the virtual screen size is too big, it winds up off-screen.
I see several guides, like thinkwiki and on debian.org that give large values for virtual. Based on my experience, I don't see how that isn't making the gdm login box off-center, or completely off-screen like I'm seeing.
So, how does one make the default and GDM resolution something pleasant and accurate, while still allowing xrandr applications to increase the resolution if desired?