Configure A System To Use Time Services
General Information
Managing time using different methods.
Time Options
- ntpd ⇒ the default in RHEL 5/6
- chronyd ⇒ the default in RHEL 7 (ntpd can still be used instead)
- Chronyd has faster time sync than ntpd and can recover from network connection problems faster.
Chrony
Two new RHEL 7 tools:
- chronyd - new red hat 7 time daemon (ntpd was previous daemon)
- timedatectl - time and date settings information
View current detailed time information
timedatectl
View available timezones
timedatectl list-timezones
Set timezone
timedatectl set-timezone America/Chicago
Set system clock to 12:30pm and 10 seconds:
timedatectl set-time 12:30:10
Enable the use of NTP for time
timedatectl set-ntp true
NTP service config file (chronyd)
- /etc/chrony.conf
NTP server entry examples in /etc/chrony.conf
server 0.pool.ntp.org iburst server 1.pool.ntp.org iburst server 2.pool.ntp.org iburst server 3.pool.ntp.org iburst
- If you make any changes, chronyd service must be restarted
Check status of NTP service, Restart it
systemctl status chronyd systemctl restart chronyd
View NTP sources
chronyc sources -v