The Legacy Time Daemon
Keeping accurate time is critical for any Linux server, ensuring that logs match up, SSL certificates validate correctly, and database clusters remain in sync. For decades, the standard way to achieve this was by running the ntp (Network Time Protocol) daemon (often the ntpd service). It actively polled external time servers and meticulously adjusted the local clock.
However, in modern versions of Ubuntu, systemd includes a built-in, lightweight SNTP client called systemd-timesyncd. For the vast majority of servers and desktop PCs, systemd-timesyncd is perfectly adequate, consuming less memory and starting faster than the legacy ntp daemon. If you have installed the older ntp package (perhaps following an outdated tutorial) and want to revert to the modern, streamlined systemd time synchronization method, you should disable and remove the legacy service.
How to Disable the NTP Service
You can stop the legacy daemon and re-enable the systemd time service via the terminal.
- Open your Ubuntu Terminal or connect via SSH.
- Stop the legacy ntp service immediately:
sudo systemctl stop ntp.service- Disable the legacy service from starting at boot:
sudo systemctl disable ntp.service- (Recommended) If you no longer need it, remove the package entirely to prevent conflicts:
sudo apt-get remove --purge ntp- Now, enable and start the modern systemd replacement:
sudo systemctl enable --now systemd-timesyncd.serviceYour Ubuntu system is now using the modern, built-in systemd-timesyncd service to maintain accurate time, allowing you to safely discard the older, heavier NTP daemon.