Hands-on Lab·Red Hat Certified System Administrator
Time Synchronization with Chrony
One objective, one config file, and one thing worth insisting on: systemctl is-active chronyd proves the service runs, not that the clock is right. chronyc tracking and timedatectl are what answer the question the objective actually asks.
Deploy and Maintain Guide 46 of 67 Beginner
- OSRHEL 10.0
- Kernel6.12.0-55.9.1.el10_0
- dnf4.20.0
- Flatpak1.16.0
- TimeAbout 11 min
chrony replaced ntpd on RHEL 7 and there is no ntpd to fall back on. The config is /etc/chrony.conf, the control tool is chronyc, and timedatectl is systemd's read-only-ish view of the same state.
| Server Name | IP Address | OS | Roles | CPU | RAM | HDD |
|---|---|---|---|---|---|---|
| RHCSA-A01 | 192.168.0.31 | RHEL 10.0 | Practice node (graded) - spare /dev/sda | 2 Core | 4 GB | 50 GB + 15 GB |
This guide includes
Use this for one objective with one configuration file. This matters because systemctl is-active tells you the service is running - it does not tell you the clock is synchronised, which is an entirely different question.
- finding what is configured
- asking whether it is actually synchronised, which is not the same as running
- changing the server, in a single line
Before you start
- A sudo-capable account.
- The session edits
/etc/chrony.confand restores it from a backup.
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What is configured
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Is it actually synchronised
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Changing the server