How to Resolve PRVG-13606 : chrony daemon is not synchronized with any external

PRVG-13606

Saw PRVG-13606 when I verify the RAC environment by runcluvfy.sh before actually installing grid infrastructure.

[grid@primary01 ~]$ cd $ORACLE_HOME
[grid@primary01 grid]$ ./runcluvfy.sh stage -pre crsinst -n primary01,primary02 -verbose
...
Verifying Network Time Protocol (NTP) ...FAILED
  Verifying chrony daemon is synchronized with at least one external time
  source ...FAILED
  primary01: PRVG-13606 : chrony daemon is not synchronized with any external
             time source on node "primary01".

It seems that chronyd is working, but it's not synced with any NTP server.

[root@primary01 ~]# systemctl status chronyd
● chronyd.service - NTP client/server
   Loaded: loaded (/usr/lib/systemd/system/chronyd.service; enabled; vendor preset: enabled)
   Active: active (running) since Sun 2021-02-14 18:47:58 CST; 16min ago
     Docs: man:chronyd(8)
           man:chrony.conf(5)
  Process: 693 ExecStartPost=/usr/libexec/chrony-helper update-daemon (code=exited, status=0/SUCCESS)
  Process: 667 ExecStart=/usr/sbin/chronyd $OPTIONS (code=exited, status=0/SUCCESS)
 Main PID: 686 (chronyd)
   CGroup: /system.slice/chronyd.service
           └─686 /usr/sbin/chronyd

Feb 14 18:47:58 primary01.example.com systemd[1]: Starting NTP client/server...
Feb 14 18:47:58 primary01.example.com chronyd[686]: chronyd version 3.2 starting (+CMDMON +NTP +REFCLOCK +RTC +PRIVDROP +SCFILTER +...DEBUG)
Feb 14 18:47:58 primary01.example.com chronyd[686]: Frequency 0.000 +/- 1000000.000 ppm read from /var/lib/chrony/drift
Feb 14 18:47:58 primary01.example.com systemd[1]: Started NTP client/server.
Hint: Some lines were ellipsized, use -l to show in full.

There's also nothing particular from the status. So we check the configuration of chronyd.

[root@primary01 ~]# vi /etc/chrony.conf
...
server 0.ol.pool.ntp.org iburst
server 1.ol.pool.ntp.org iburst
server 2.ol.pool.ntp.org iburst
server 3.ol.pool.ntp.org iburst

Let's check whether we can connect to NTP servers or not.

[root@primary01 ~]# nslookup 0.ol.pool.ntp.org
Server:         192.168.0.199
Address:        192.168.0.199#53

** server can't find 0.ol.pool.ntp.org: NXDOMAIN

[root@primary01 ~]# nslookup 1.ol.pool.ntp.org
Server:         192.168.0.199
Address:        192.168.0.199#53

** server can't find 1.ol.pool.ntp.org: NXDOMAIN

[root@primary01 ~]# nslookup 2.ol.pool.ntp.org
Server:         192.168.0.199
Address:        192.168.0.199#53

** server can't find 2.ol.pool.ntp.org: NXDOMAIN

[root@primary01 ~]# nslookup 3.ol.pool.ntp.org
Server:         192.168.0.199
Address:        192.168.0.199#53

** server can't find 3.ol.pool.ntp.org: NXDOMAIN

No, we can't reach them.

Solution

We should replace those time servers with available ones to solve PRVG-13606. For example, *.jp.pool.ntp.org are working time servers. You can use NTP servers near your location.

[root@primary01 ~]# nslookup 0.jp.pool.ntp.org
Server:         192.168.0.199
Address:        192.168.0.199#53

Non-authoritative answer:
Name:   0.jp.pool.ntp.org
Address: 172.104.118.14
Name:   0.jp.pool.ntp.org
Address: 157.7.153.56
Name:   0.jp.pool.ntp.org
Address: 3.114.30.212
Name:   0.jp.pool.ntp.org
Address: 103.202.216.35

We modify the configuration file of chronyd as below.

[root@primary01 ~]# vi /etc/chrony.conf
...
server 0.jp.pool.ntp.org iburst
server 1.jp.pool.ntp.org iburst
server 2.jp.pool.ntp.org iburst
server 3.jp.pool.ntp.org iburst

Don't forget to restart chronyd daemon.

[root@primary01 ~]# systemctl restart chronyd

There's a successful installation of grid infrastructure 19c can be found in this website.