+* ValidNoProcess= ? ContinueAfterExit=, ActiveAfterExit=, KeepAfterExit=
+ (after this change update udev service files)
+
+* systemd.log_level=debug should overwrite 'quiet' ?
+
+* implicit 'default.target' ?
+ systemd currently fails to boot when the link is dangling, like
+ after the move of the runlevel targets from /etc to /lib
+