I switched AppArmor for ntpd into "complain" mode
$ sudo aa-complain /usr/sbin/ntpd Setting /usr/sbin/ntpd to complain mode.
after that the ntpd "-N" flag started to work.
$ (ps alx | head -1) ; (ps alx | grep ntpd) | grep -v grep F UID PID PPID PRI NI VSZ RSS WCHAN STAT TTY TIME COMMAND 5 117 14798 1 -100 - 38736 2096 poll_s Ss ? 0:00 /usr/sbin/ntpd -p /var/run/ntpd.pid -g -N -c /var/lib/ntp/ntp.conf.dhcp -u 117:126
PRI=1 NI=-100
I switched AppArmor for ntpd into "complain" mode
$ sudo aa-complain /usr/sbin/ntpd
Setting /usr/sbin/ntpd to complain mode.
after that the ntpd "-N" flag started to work.
$ (ps alx | head -1) ; (ps alx | grep ntpd) | grep -v grep ntp/ntp. conf.dhcp -u 117:126
F UID PID PPID PRI NI VSZ RSS WCHAN STAT TTY TIME COMMAND
5 117 14798 1 -100 - 38736 2096 poll_s Ss ? 0:00 /usr/sbin/ntpd -p /var/run/ntpd.pid -g -N -c /var/lib/
PRI=1 NI=-100