Erik Christiansen wrote:
$ xinit /usr/bin/xterm -ms red
X: user not authorized to run the X server, aborting.
By default, you are only allowed to start X if 1) you're root; or 2) you're logged in at the console (i.e. tty1 through ttyN). As you say, this can be turned off:
Apparently I can "fix" that by setting "allowed_users=anybody" in /etc/X11/Xwrapper.config
...but you should avoid doing so unless you understand the risks.
$ su - # xinit /usr/bin/xterm -ms red
Fatal server error: Server is already active for display 0
This is, of course, because you already have an X server running on the default port (:0, or 7000 in TCP terms). Either turn off X (probably log out of X and then "sudo /etc/init.d/gdm stop"), or create a second X server: xinit /usr/bin/xterm -ms red -- /usr/bin/Xorg :1
Incidentally, one google hit mentioned a bug in the Mint distro which caused "-ms" to do nothing. While that was a couple of years back, perhaps it's present in ubuntu as well.
I can't comment on that unless you cite the URL.