Description of problem:
After updating to XServer 1.10 X fails to start with the message (in /var/log/kdm.log): "Fatal server error: Unrecognized option: -nr".
The flag "-nr" (ServerArgsLocal=-nr -nolisten tcp in /etc/kde/kdm/kdmrc) is 'replaced' by the flag "-background none", see . Just replacing "-nr" by "-background none" is not enough... :-(
Version-Release number of selected component (if applicable):
Just boot into fc15 and kdm as login manager
X crashes, no kdm login
X does not crash, kdm login
Thanks for the heads-up.
Changing kdmrc options *may* require a reboot (or runlevel change, Restarting X session often isn't enough). How did you test?
1. I normally tried to (re)boot -> black screen -> "Fatal server error
Unrecognized option: -nr"
2. Booted into text mode (runlevel 3) -> replaced "-nr" by "-background none"
in /etc/kde/kdm/kdmrc -> "Fatal server error:
xf86OpenConsole: VT_WAITACTIVE failed: Interrupted system call"
He, this one have we see before :-) 
3. For the time being I boot without Plymouth.
Well, we'll give s/-nr/-background none/ a try,
* Fri Dec 03 2010 Rex Dieter <firstname.lastname@example.org> - 4.6-2
- drop old Conflicts
- Xserver-1.10: Fatal server error: Unrecognized option: -nr (#659684)
Are you sure it will be enough to change "-nr" by "-background none"? I've tried it but that didn't work. See comment #2.
May be Peter Hutterer can tell you more. He created the patches for gdm.
Well, if that change is not sufficient, then there is an additional bug also triggered by the new X server, separate from this one.
For gdm Peter Hutterer is doing the following:
diff --git a/plymouth.patch b/plymouth.patch
index 0658664..b74aaac 100644
@@ -222,7 +222,7 @@ index ba10386..3ec21e9 100644
+ char *vt;
+ g_free (server->priv->command);
-+ server->priv->command = g_strdup (X_SERVER " -nr -verbose");
++ server->priv->command = g_strdup (X_SERVER " -background none -verbose");
+ vt = get_active_vt_as_string ();
+ res = gdm_server_spawn (server, vt);
+ g_free (vt);
You have golden fingers :-)
The changes you made to kde-settings do work (with kde 4.6 beta 2 at least).
X is running on vt1.
This report can be closed, I suppose.
thanks for the confirmation.
I've bad news :-( After rebooting a few times I got:
1. Normal boot -> login screen -> X runs on vt1 (good)
2. Server crash -> "Fatal server error: xf86OpenConsole: VT_WAITACTIVE failed: Interrupted system call"
3. Boot -> Interrupt Plymouth by pressing the ESC-key -> login screen -> X runs on vt7 (not good)
The problem seems to be related to the new boot process:
Plymouth is started by dracut and 'is taken over' by systemd. Sometimes the takeover is successful sometime it's not.
May be this report need to be reopened, sorry.
Open a new bug please, that is almost certainly a separate issue than this.
I'll file a bug against Plymouth, because the -nr flag was introduced with this package:
In  I read:
"krh has a patch which adds a -nr ("no root") option which makes the root window keep the framebuffer contents that were around when X started"
FYI: As requested I've opened bug #660461