RockyLinux＋Webmin環境設定 サーバー時間の同期設定

今現在のデフォルトはRockyLinux9＋WebminをVPSで立ち上げ＆運営で行っています。
現在はなんだかんだでKagoyaを選定。
このセットで標準ではタイムサーバーを外部の正確なサーバーと同期する仕込みは出来上がっていない。
当然ですが、日々脈々と静々と徐々に正確な時間とズレが生じてくるわけです。
この問題を解決するために、chronyをインストールして設定を行いました。
webminをサーバーのコントロールパネルとしているんで、使える便利ツールは積極的に使います。

# Use public servers from the pool.ntp.org project.
# Please consider joining the pool (https://www.pool.ntp.org/join.html).
#pool 2.rocky.pool.ntp.org iburst
pool ntp.nict.jp iburst

# Use NTP servers from DHCP.
sourcedir /run/chrony-dhcp

# Record the rate at which the system clock gains/losses time.
driftfile /var/lib/chrony/drift

# Allow the system clock to be stepped in the first three updates
# if its offset is larger than 1 second.
makestep 1.0 3

# Enable kernel synchronization of the real-time clock (RTC).
rtcsync

# Enable hardware timestamping on all interfaces that support it.
#hwtimestamp *

# Increase the minimum number of selectable sources required to adjust
# the system clock.
#minsources 2

# Allow NTP client access from local network.
#allow 192.168.0.0/16

# Serve time even if not synchronized to a time source.
#local stratum 10

# Require authentication (nts or key option) for all NTP sources.
#authselectmode require

# Specify file containing keys for NTP authentication.
keyfile /etc/chrony.keys

# Save NTS keys and cookies.
ntsdumpdir /var/lib/chrony

# Insert/delete leap seconds by slewing instead of stepping.
#leapsecmode slew

# Get TAI-UTC offset and leap seconds from the system tz database.
leapsectz right/UTC

# Specify directory for log files.
logdir /var/log/chrony

# Select which information is logged.
#log measurements statistics tracking

> timedatectl
               Local time: Wed 2025-05-28 17:08:48 JST
           Universal time: Wed 2025-05-28 08:08:48 UTC
                 RTC time: Wed 2025-05-28 08:08:48
                Time zone: Asia/Tokyo (JST, +0900)
System clock synchronized: yes
              NTP service: active
          RTC in local TZ: no
> systemctl status chronyd      #稼働状況のチェックをします
● chronyd.service - NTP client/server
     Loaded: loaded (/usr/lib/systemd/system/chronyd.service; enabled; preset: enabled)
     Active: active (running) since Tue 2025-05-27 23:45:01 JST; 19h ago
       Docs: man:chronyd(8)
             man:chrony.conf(5)
    Process: 2733344 ExecStart=/usr/sbin/chronyd $OPTIONS (code=exited, status=0/SUCCESS)
   Main PID: 2733346 (chronyd)
      Tasks: 1 (limit: 11090)
     Memory: 896.0K
        CPU: 121ms
     CGroup: /system.slice/chronyd.service
             └─2733346 /usr/sbin/chronyd -F 2

May 27 23:45:01 mail.boldwaynet.jp chronyd[2733346]: chronyd version 4.5 starting (+CMDMON +NTP +REFCLOCK +RTC +PRIVDROP +SCFILTER +SIGND +ASYNCDNS +NTS +SECHASH +IPV6 +DEBUG)
May 27 23:45:01 mail.boldwaynet.jp chronyd[2733346]: Loaded 0 symmetric keys
May 27 23:45:01 mail.boldwaynet.jp chronyd[2733346]: Using right/UTC timezone to obtain leap second data
May 27 23:45:01 mail.boldwaynet.jp chronyd[2733346]: Frequency -12.922 +/- 0.016 ppm read from /var/lib/chrony/drift
May 27 23:45:01 mail.boldwaynet.jp chronyd[2733346]: Loaded seccomp filter (level 2)
May 27 23:45:01 mail.boldwaynet.jp systemd[1]: Started NTP client/server.
May 27 23:45:01 mail.boldwaynet.jp chronyd[2733346]: System clock was stepped by 0.000000 seconds
May 27 23:45:06 mail.boldwaynet.jp chronyd[2733346]: Selected source 133.243.238.243 (ntp.nict.jp)
May 27 23:45:06 mail.boldwaynet.jp chronyd[2733346]: System clock TAI offset set to 37 seconds
May 27 23:45:07 mail.boldwaynet.jp chronyd[2733346]: Selected source 2001:df0:232:eea0::fff3 (ntp.nict.jp)

定期的に自動同期を行う

毎日1回程度で十分と思われる。
「ハードウェア」⇒「システム時間」⇒「タイムサーバーの同期」で設定する。