Hello, friends. In this post, we’ll show you how to set up an NTP server by installing Chrony on Ubuntu 20.04
An NTP server is important because it allows all devices on a network to be synchronized via a clock. That is, they all have the same time and time zone. This may seem unimportant, but the correct functioning of many services depends on proper time settings.
Now, there is a tool called Chrony that allows us to quickly deploy an NTP server.
According to the Chrony website:
Chrony is a versatile implementation of the Network Time Protocol (NTP). It can synchronize the system clock with NTP servers, reference clocks (e.g. GPS receiver), and manual input using wristwatch and keyboard. It can also operate as an NTPv4 (RFC 5905) server and peer to provide a time service to other computers in the network.
Fortunately, it has good support for many Linux distributions and Ubuntu is no exception.
Chrony on Ubuntu 20.04
Before starting, the server must have the time zone set correctly.
So, open a terminal or connect via SSH.
sudo timedatectl set-timezone Europe/Berlin
Replace Europe/Berlin with the correct timezone for your server.
To check the changes, run the command timedatectl.
Output:
Local time: Wed 2021-05-12 21:13:11 CEST
Universal time: Wed 2021-05-12 19:13:11 UTC
RTC time: Wed 2021-05-12 19:13:12
System clock synchronized: yes
NTP service: active
Time zone: Europe/Berlin (CEST, +0200)
RTC in local TZ: no
Now we can install the chrony package from the official Ubuntu 20.04 repositories.
sudo apt update sudo apt install chrony Reading package lists... Done Building dependency tree Reading state information... Done The following packages will be REMOVED: systemd-timesyncd The following NEW packages will be installed: chrony 0 upgraded, 1 newly installed, 1 to remove and 11 not upgraded. Need to get 220 kB of archives. After this operation, 290 kB of additional disk space will be used. Do you want to continue? [Y/n]
The program is quite lightweight so the installation will take almost no time at all.
So, start the Chrony service and have it start with the system.
sudo systemctl start chronyd sudo systemctl enable chronyd
Check the status of the service
sudo systemctl status chronyd
● chrony.service - chrony, an NTP client/server
Loaded: loaded (/lib/systemd/system/chrony.service; enabled; vendor preset: enabled)
Active: active (running) since Wed 2021-05-12 21:16:25 CEST; 1min 36s ago
Docs: man:chronyd(8)
man:chronyc(1)
man:chrony.conf(5)
Main PID: 1815 (chronyd)
Tasks: 2 (limit: 2286)
Memory: 1.0M
CGroup: /system.slice/chrony.service
├─1815 /usr/sbin/chronyd -F -1
└─1816 /usr/sbin/chronyd -F -1
May 12 21:16:25 osradar systemd[1]: Starting chrony, an NTP client/server...
May 12 21:16:25 osradar chronyd[1815]: chronyd version 3.5 starting (+CMDMON +NTP +REFCLOCK +RTC +PRIVDROP +SCFILTER +SIGND +ASYNCDNS +SECHASH +IPV6 -DEBUG)
May 12 21:16:25 osradar chronyd[1815]: Initial frequency -38.890 ppm
May 12 21:16:25 osradar chronyd[1815]: Loaded seccomp filter
May 12 21:16:25 osradar systemd[1]: Started chrony, an NTP client/server.
May 12 21:16:32 osradar chronyd[1815]: Selected source 2001:67c:1560:8003::c7
May 12 21:17:38 osradar chronyd[1815]: Selected source 2001:1600:4:1::123
And you will know that the service is running correctly.
Configuring Chrony on Ubuntu 20.04
Now that we have the service installed, we need to configure it. The Chorny configuration file is /etc/chrony/chrony.conf which we need to modify but first make a backup of it.
sudo cp /etc/chrony/chrony/chrony.conf `/etc/chrony/chrony.conf.bak
And now edit it:
sudo nano /etc/chrony/chrony.conf
And set the nearest NTP servers
server [NTP server]
Then save the changes and close the editor.
Now do the synchronization
sudo timedatectl set-ntp true
After that, restart the Chrony service.
sudo systemctl restart chronyd
Then, test the changes by checking the Chrony sources
chronyc sources
Output
210 Number of sources = 8 MS Name/IP address Stratum Poll Reach LastRx Last sample =============================================================================== ^- golem.canonical.com 2 6 37 5 +6082us[+6082us] +/- 54ms ^- chilipepper.canonical.com 2 6 67 3 +313us[ +313us] +/- 47ms ^- alphyn.canonical.com 2 6 37 5 +892us[ +892us] +/- 119ms ^+ pugot.canonical.com 2 6 37 4 +1452us[+1452us] +/- 71ms ^* 25000-021.cloud.services> 2 6 37 6 +881us[ -83us] +/- 48ms ^- ns1.luns.net.uk 2 6 37 4 +2533us[+2533us] +/- 67ms ^+ 2a01:4f8:c2c:3d20::1 3 6 37 4 -1651us[-1651us] +/- 93ms ^+ time02.nevondo.com 2 6 37 4 +1028us[+1028us] +/- 43ms
So, everything is correct.
Note: I am uing the default server. In this output, you will see the server that you added.
Configuring the Chrony Client
Now it’s time to do the client configuration. Regardless of the Linux distribution you use, you have to set the Timezone correctly.
sudo timedatectl set-timezone Europe/Berlin
Proceed now to install the client on your distribution.
For example, on CentOS it would be
sudo dnf install chony
Or on Debian based distributions:
sudo apt install chrony
Next, you have to configure Chrony to serve the server you have configured.
sudo nano /etc/chrony/chrony.conf
And add the Chrony server:
server chrony-server-ip
Save the changes and close the editor. Now synchronise your computer with the created NTP server.
sudo timedatectl set-ntp true
You can also verify the changes by running
chronyc sources
So, enjoy it.
Conclusion
An NTP server is a simple tool to set up but it will help you to keep everything in order on your network. This step is essential for many computer systems.
