AWS Ubuntu NTP設定方法¶

サービスの開始

sudo /etc/init.d/chrony start

[ ok ] Starting chrony (via systemctl): chrony.service.

時刻を同期させていることの確認

chronyc sources -v

Amazon Time Sync ServiceのIPアドレス:169.254.169.123を使用していることを確認
210 Number of sources = 1

  .-- Source mode  '^' = server, '=' = peer, '#' = local clock.
 / .- Source state '*' = current synced, '+' = combined , '-' = not combined,
| /   '?' = unreachable, 'x' = time may be in error, '~' = time too variable.
||                                                 .- xxxx [ yyyy ] +/- zzzz
||      Reachability register (octal) -.           |  xxxx = adjusted offset,
||      Log2(Polling interval) --.      |          |  yyyy = measured offset,
||                                \     |          |  zzzz = estimated error.
||                                 |    |           \
MS Name/IP address         Stratum Poll Reach LastRx Last sample
===============================================================================
^* 169.254.169.123               3   6    17    27  +1967ns[+5612ns] +/-  364us

時刻同期のメトリクスを確認

chronyc tracking

（例）
Reference ID    : A9FEA97B (169.254.169.123)
Stratum         : 4
Ref time (UTC)  : Thu Aug 20 04:33:27 2020
System time     : 0.000000004 seconds slow of NTP time
Last offset     : +0.000003645 seconds
RMS offset      : 0.000003645 seconds
Frequency       : 0.704 ppm fast
Residual freq   : -0.549 ppm
Skew            : 0.020 ppm
Root delay      : 0.000232039 seconds
Root dispersion : 0.000348835 seconds
Update interval : 2.0 seconds
Leap status     : Normal

サービスの自動起動を有効化する

systemctl enable chrony

Synchronizing state of chrony.service with SysV service script with /lib/systemd/systemd-sysv-install.
Executing: /lib/systemd/systemd-sysv-install enable chrony
Created symlink /etc/systemd/system/chronyd.service → /lib/systemd/system/chrony.service.
Created symlink /etc/systemd/system/multi-user.target.wants/chrony.service → /lib/systemd/system/chrony.service.

サービス自動起動の設定を確認する

systemctl is-enabled chrony

enabled