Reenabled systemd-timesyncd and am back to chrony not starting on boot so at least I can reproduce at will. Here are the outputs:
$ sudo systemd-analyze critical-chain
The time after the unit is active or started is printed after the "@" character.
The time the unit takes to start is printed after the "+" character.
$ sudo journalctl -o short-monotonic -u systemd-timesyncd.service -u chrony.service | head -n 20
-- Logs begin at Thu 2018-05-31 12:51:22 WEST, end at Thu 2018-07-05 18:23:07 WEST. --
[ 2.756688] coulson systemd[1]: Starting Network Time Synchronization...
[ 2.865804] coulson systemd[1]: Started Network Time Synchronization.
[ 33.233208] coulson systemd-timesyncd[292]: Synchronized to time server [2001:67c:1560:8003::c8]:123 (ntp.ubuntu.com).
[ 722.864694] coulson systemd[1]: Stopping Network Time Synchronization...
[ 722.900591] coulson systemd[1]: Stopped Network Time Synchronization.
-- Reboot --
[ 9.812874] coulson systemd[1]: Starting Network Time Synchronization...
[ 9.949073] coulson systemd[1]: Started Network Time Synchronization.
[ 40.394096] coulson systemd-timesyncd[573]: Synchronized to time server [2001:67c:1560:8003::c7]:123 (ntp.ubuntu.com).
[10529.558443] coulson systemd-timesyncd[573]: Synchronized to time server [2001:67c:1560:8003::c8]:123 (ntp.ubuntu.com).
[20405.821605] coulson systemd-timesyncd[573]: Synchronized to time server [2001:67c:1560:8003::c8]:123 (ntp.ubuntu.com).
[29239.165550] coulson systemd-timesyncd[573]: Synchronized to time server 91.189.89.199:123 (ntp.ubuntu.com).
[34935.400396] coulson systemd-timesyncd[573]: Synchronized to time server 91.189.89.198:123 (ntp.ubuntu.com).
[64222.761628] coulson systemd-timesyncd[573]: Synchronized to time server 91.189.89.198:123 (ntp.ubuntu.com).
[77531.401846] coulson systemd-timesyncd[573]: Synchronized to time server [2001:67c:1560:8003::c8]:123 (ntp.ubuntu.com).
[79656.970968] coulson systemd[1]: Starting chrony, an NTP client/server...
[79656.971139] coulson systemd[1]: Stopping Network Time Synchronization...
[79656.997189] coulson systemd[1]: Stopped Network Time Synchronization.
[79657.110021] coulson chronyd[23591]: chronyd version 3.2 starting (+CMDMON +NTP +REFCLOCK +RTC +PRIVDROP +SCFILTER +SECHASH +SIGND +ASYNCDNS +IPV6 -DEBUG)
Seems like after reboot chrony wasn't even attempted to start even though it's still enabled:
Reenabled systemd-timesyncd and am back to chrony not starting on boot so at least I can reproduce at will. Here are the outputs:
$ sudo systemd-analyze critical-chain
The time after the unit is active or started is printed after the "@" character.
The time the unit takes to start is printed after the "+" character.
graphical.target @32.789s service @12.224s +1.060s online. target @12.222s ─NetworkManager -wait-online. service @4.481s +7.740s
└─NetworkManag er.service @4.211s +250ms
└─dbus. service @4.007s
└─ basic.target @3.972s
└─sockets. target @3.972s
└─uuidd. socket @3.972s
└─sysinit. target @3.970s
└ ─systemd- timesyncd. service @3.840s +129ms
└─systemd- tmpfiles- setup.service @3.827s +11ms
└─local- fs.target @3.824s
└─ run-user- 1000-gvfs. mount @13.514s
└─run-user- 1000.mount @12.399s
└─local- fs-pre. target @297ms
└─keyboard- setup.service @196ms +100ms
└ ─systemd- journald. socket @193ms
└─system. slice @193ms
└─-. slice @191ms
└─multi-user.target @32.789s
└─owserver.
└─network-
└
$ sudo journalctl -o short-monotonic -u systemd- timesyncd. service -u chrony.service | head -n 20 timesyncd[ 292]: Synchronized to time server [2001:67c: 1560:8003: :c8]:123 (ntp.ubuntu.com). timesyncd[ 573]: Synchronized to time server [2001:67c: 1560:8003: :c7]:123 (ntp.ubuntu.com). timesyncd[ 573]: Synchronized to time server [2001:67c: 1560:8003: :c8]:123 (ntp.ubuntu.com). timesyncd[ 573]: Synchronized to time server [2001:67c: 1560:8003: :c8]:123 (ntp.ubuntu.com). timesyncd[ 573]: Synchronized to time server 91.189.89.199:123 (ntp.ubuntu.com). timesyncd[ 573]: Synchronized to time server 91.189.89.198:123 (ntp.ubuntu.com). timesyncd[ 573]: Synchronized to time server 91.189.89.198:123 (ntp.ubuntu.com). timesyncd[ 573]: Synchronized to time server [2001:67c: 1560:8003: :c8]:123 (ntp.ubuntu.com).
-- Logs begin at Thu 2018-05-31 12:51:22 WEST, end at Thu 2018-07-05 18:23:07 WEST. --
[ 2.756688] coulson systemd[1]: Starting Network Time Synchronization...
[ 2.865804] coulson systemd[1]: Started Network Time Synchronization.
[ 33.233208] coulson systemd-
[ 722.864694] coulson systemd[1]: Stopping Network Time Synchronization...
[ 722.900591] coulson systemd[1]: Stopped Network Time Synchronization.
-- Reboot --
[ 9.812874] coulson systemd[1]: Starting Network Time Synchronization...
[ 9.949073] coulson systemd[1]: Started Network Time Synchronization.
[ 40.394096] coulson systemd-
[10529.558443] coulson systemd-
[20405.821605] coulson systemd-
[29239.165550] coulson systemd-
[34935.400396] coulson systemd-
[64222.761628] coulson systemd-
[77531.401846] coulson systemd-
[79656.970968] coulson systemd[1]: Starting chrony, an NTP client/server...
[79656.971139] coulson systemd[1]: Stopping Network Time Synchronization...
[79656.997189] coulson systemd[1]: Stopped Network Time Synchronization.
[79657.110021] coulson chronyd[23591]: chronyd version 3.2 starting (+CMDMON +NTP +REFCLOCK +RTC +PRIVDROP +SCFILTER +SECHASH +SIGND +ASYNCDNS +IPV6 -DEBUG)
Seems like after reboot chrony wasn't even attempted to start even though it's still enabled:
$ sudo systemctl is-enabled chrony
enabled