Reconfiguring the X server on Debian
This is one of those tasks that I do infrequently and forget how it work…
I just got a nice big new monitor !
The command is dpkg-reconfigure xserver-xfree86
But this will silently fail to update the XF86Config-4 file if the file has been modified, if you read the file carefully you will see a useful explanation - but I missed this.
# XF86Config-4 (XFree86 X Window System server configuration file)
#
# This file was generated by dexconf, the Debian X Configuration tool, using
# values from the debconf database.
#
# Edit this file with caution, and see the XF86Config-4 manual page.
# (Type "man XF86Config-4" at the shell prompt.)
#
# This file is automatically updated on xserver-xfree86 package upgrades *only*
# if it has not been modified since the last upgrade of the xserver-xfree86
# package.
#
# If you have edited this file but would like it to be automatically updated
# again, run the following commands as root:
#
# cp /etc/X11/XF86Config-4 /etc/X11/XF86Config-4.custom
# md5sum /etc/X11/XF86Config-4 >/var/lib/xfree86/XF86Config-4.md5sum
# dpkg-reconfigure xserver-xfree86
see also