RHEL/OEL 7 – NTPD replaced by Chrony

Despite configuring NTP during the installation process, NTPD is not installed /configured/running after the installation completes.

date_time

New fresh installation of  RHEL/OEL 7 the default NTP Client is the CHRONY.

What is the CHRONY?
Chrony was introduced as new NTP client provided in the chrony package. Chrony does not provides all features available in old ntp client (ntp). So ntp is still provided due to compatibility.

During Oracle Grid Infrastructure Installation the runInstaller will   fail during  prerequisite  check due ntp not configured.

NTP not configured. Network Time Protocol (NTP)  - Failed 
PRVF-7590 : "ntpd" is not running on node "xxx"

Oracle recommend to use NTPD and disable CHRONYD.

Just follow step below to Install/Configure/Enable NTPD

1. Check Chronyd service

# systemctl status chronyd.service
● chronyd.service - NTP client/server
 Loaded: loaded (/usr/lib/systemd/system/chronyd.service; enabled; vendor preset: enabled)
 Active: active (running) since Mon 2016-05-30 01:15:33 BRT; 5s ago
 Process: 19464 ExecStartPost=/usr/libexec/chrony-helper update-daemon (code=exited, status=0/SUCCESS)
 Process: 19456 ExecStart=/usr/sbin/chronyd $OPTIONS (code=exited, status=0/SUCCESS)
 Main PID: 19459 (chronyd)
 CGroup: /system.slice/chronyd.service
 └─19459 /usr/sbin/chronyd

May 30 01:15:33 node1 systemd[1]: Starting NTP client/server...
May 30 01:15:33 node1 chronyd[19459]: chronyd version 2.1.1 starting (+CMDMON +NTP +REFCLOCK +RTC +PRIVDROP +DEBUG +ASYNCDNS +IPV6 +SECHASH)
May 30 01:15:33 node1 chronyd[19459]: Frequency -23.731 +/- 0.023 ppm read from /var/lib/chrony/drift
May 30 01:15:33 node1 systemd[1]: Started NTP client/server.

2. Stop and disable Chronyd service

# systemctl stop chronyd.service
# systemctl disable chronyd.service
Removed symlink /etc/systemd/system/multi-user.target.wants/chronyd.service.

3. Install ntpd package

# yum install ntp -y

4. Add “-x ” option into  the “/etc/sysconfig/ntpd” file.

OPTIONS="-x -u ntp:ntp -p /var/run/ntpd.pid"

5. Enable and Start NTPD

#systemctl enable ntpd.service
Created symlink from /etc/systemd/system/multi-user.target.wants/ntpd.service to /usr/lib/systemd/system/ntpd.service.


# systemctl start ntpd.service

# systemctl status ntpd.service
● ntpd.service - Network Time Service
 Loaded: loaded (/usr/lib/systemd/system/ntpd.service; enabled; vendor preset: disabled)
 Active: active (running) since Mon 2016-05-30 01:23:09 BRT; 9s ago
 Process: 23048 ExecStart=/usr/sbin/ntpd -u ntp:ntp $OPTIONS (code=exited, status=0/SUCCESS)
 Main PID: 23050 (ntpd)
 CGroup: /system.slice/ntpd.service
 └─23050 /usr/sbin/ntpd -u ntp:ntp -x -u ntp:ntp -p /var/run/ntpd.pid

May 30 00:27:07 node1 ntpd[2829]: Listen normally on 10 virbr0 192.168.122.1 UDP 123
May 30 00:27:07 node1 ntpd[2829]: Listen normally on 11 lo ::1 UDP 123
May 30 00:27:07 node1 ntpd[2829]: Listen normally on 12 eno16777984 fe80::250:56ff:fe90:21e9 UDP 123
May 30 00:27:07 node1 ntpd[2829]: Listen normally on 13 eno33559296 fe80::250:56ff:fe90:d421 UDP 123
May 30 00:27:07 node1 ntpd[2829]: Listen normally on 14 eno50338560 fe80::250:56ff:fe90:f203 UDP 123
May 30 00:27:07 node1 ntpd[2829]: Listening on routing socket on fd #31 for interface updates
May 30 00:27:07 node1 systemd[1]: Started Network Time Service.
May 30 00:27:08 node1 ntpd[2829]: 0.0.0.0 c016 06 restart
May 30 00:27:08 node1 ntpd[2829]: 0.0.0.0 c012 02 freq_set ntpd 0.000 PPM
May 30 00:27:08 node1 ntpd[2829]: 0.0.0.0 c011 01 freq_not_set

Known issues that are solved using above procedure.

# ntpq -p
localhost: timed out, nothing received
***Request timed out
# ntpstat 
Unable to talk to NTP daemon.  Is it running?