Useful dual-head configuration requires manual editing of xorg.conf to set Virtual
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
gnome-control-center |
Fix Released
|
Medium
|
|||
gnome-control-center (Ubuntu) |
Fix Released
|
Low
|
Ubuntu Desktop Bugs | ||
xorg (Ubuntu) |
Invalid
|
High
|
Unassigned |
Bug Description
Binary package hint: xorg
Users upgrading from Dapper Drake to Hardy Heron who have used Xinerama to support dual monitors now have to use a different method (xrandr I think). This isn't mentioned in the release notes and the graphical tool for configuring dual monitors is under "Screen Resolution" in the System -> Preferences Menu. The point being that it is quite hard to find.
Users with multiple desktops appear to have add the following to the xorg.conf file "Screen" section:
SubSection "Display"
Depth 24
Virtual 4000 2048
EndSubSection
Then the screen resolution tool works fine for me.
A note in the release notes like the following might help:
"Ubuntu 8.04 changes the way dual monitors are supported. Users should edit the xorg.conf file and then use the System -> Preferences -> Screen Resolution tool to configure dual monitors on their system. "
[More Info]
You should set your Virtual size to the maximum height and width of your combined displays. So if you have two 1600x1200 displays you want to place one beside the other, use Virtual 3200x1200.
Note that setting Virtual to greater than 2048 in either height or width will prevent DRI from loading, which means that Compiz cannot be used (bug #146859). The absolute maximum is 8192x8192. These limits will probably go away in Intrepid after TTM is integrated.
Related branches
Changed in xorg: | |
assignee: | nobody → bryceharrington |
importance: | Undecided → High |
milestone: | none → ubuntu-8.04.1 |
status: | New → Confirmed |
description: | updated |
description: | updated |
Changed in xorg: | |
assignee: | bryceharrington → nobody |
Changed in xorg: | |
status: | Confirmed → Triaged |
Changed in gnome-control-center: | |
status: | Unknown → Confirmed |
Changed in gnome-control-center: | |
status: | Confirmed → Fix Released |
Changed in gnome-control-center: | |
importance: | Unknown → Medium |
I've documented this at https:/ /wiki.ubuntu. com/X/Config.
A mention in the release notes sounds wise as well, although it's too late for 8.04, but we could put a note into 8.04.1. I wasn't even certain the feature would be available (and functional) in time for the release, so we didn't advertise it in the release notes.
However, I'm betting most people won't look at release notes. An alternate solution would be to check the current Virtual size in the applet when setting dual screen modes; I think this can be done entirely with just libXrandr calls in C. Then, if the selected size would exceed the current maximum Virtual size, it should display a warning dialog to the user mentioning the need to edit xorg.conf to make that setting.
An even better solution would be to include something to edit the xorg.conf for them automagically, however given the wide amount of variations in xorg.conf's out in the wild, I would worry that such a "feature" could end up causing a lot of damage. Plus, the effort would be a waste since for Intrepid the need for specifying Virtual should go away entirely. So I am not going to attempt to do this auto-editing, but if anyone else has a moment of brilliance and comes up with a stunning (and lo-risk) patch, I'd be very interested.