systemd-timesyncd unit still running after installation of ntp package

[Nathan Stratton Treadway]

I recently installed the ntp package on a fairly vanilla installed-from-DVD Xenial system, and noticed that after the package installation both systemd-timesyncd and ntp were running:

# systemctl status ntp systemd-timesyncd.service --no-pager
 ntp.service - LSB: Start NTP daemon
   Loaded: loaded (/etc/init.d/ntp; bad; vendor preset: enabled)
   Active: active (running) since Tue 2016-06-28 19:21:16 HDT; 6min ago
     Docs: man:systemd-sysv-generator(8)
   CGroup: /system.slice/ntp.service
           3364 /usr/sbin/ntpd -p /var/run/ntpd.pid -g -u 112:118

[...log lines...]

 systemd-timesyncd.service - Network Time Synchronization
   Loaded: loaded (/lib/systemd/system/systemd-timesyncd.service; enabled; vendor preset: enabled)
  Drop-In: /lib/systemd/system/systemd-timesyncd.service.d
           `-disable-with-time-daemon.conf
   Active: active (running) since Sun 2016-06-26 06:53:05 HDT; 2 days ago
     Docs: man:systemd-timesyncd.service(8)
 Main PID: 821 (systemd-timesyn)
   Status: "Synchronized to time server 91.189.89.199:123 (ntp.ubuntu.com)."
   CGroup: /system.slice/systemd-timesyncd.service
           821 /lib/systemd/systemd-timesyncd

[...log lines...]

I was able to do "systemctl stop systemd-timesyncd.service" manually without any trouble, but presumably if I hadn't noticed the situation I might have had problems with the two services both running simultaneously until my next reboot.

(Once the systemd-timesyncd service is stopped, it is prevented from starting again by the constraint in the disable-with-time-daemon.conf file.)

[Nathan Stratton Treadway (nathanst)]

Here are my current versions of the affected packages:
# dpkg -l ntp systemd | cat
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
+++-==============-=======================-============-=================================================
ii ntp 1:4.2.8p4+dfsg-3ubuntu5 amd64 Network Time Protocol daemon and utility programs
ii systemd 229-4ubuntu6 amd64 system and service manager

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[David Britton (dpb)]

Hi There, thanks for the bug report --

This is fixed in the Ubuntu development release: Artful. ntpd now ships a systemd job that conflicts with systemd-timesyncd.service that prevents the duplicate service running. Confirmed on a deployment of the latest Artful as of this comment.

[Andres Rodriguez (andreserl)]

FWIW, this issue is still present in older releases. Effectively, if NTP is installed and configured to access X ntp server and timesyncd would still try to fallback to ntp.ubuntu.com.

In proxied environments, this will result in ntp.ubuntu.com being unavailable.

[David Britton (dpb)]

@andreserl -- does this just fill up the error log on old releases or is there a functional impact?