What is the /etc/resolv.conf file
cluvfy fails with PRVG-13602 : NTP daemon is not synchronized with any external time source on node "node1"
Following is an example,where the ntp.conf is configured with Time Source Servers -
$ cat /etc/ntp.conf
driftfile /var/lib/ntp/drift
restrict default kod nomodify notrap nopeer noquery
restrict -6 default kod nomodify notrap nopeer noquery
restrict 127.0.0.1
restrict -6 ::1
restrict 10.206.2.0 mask 255.255.255.0 nomodify notrap
server ntp-server1 iburst dynamic
server ntp-server2 iburst dynamic
tos maxdist 30
includefile /etc/ntp/crypto/pw
keys /etc/ntp/keys
However,when the Time Source is checked using the below command -
$ /usr/sbin/ntpq -p
remote refid st t when poll reach delay offset jitter
==============================================================================
+10.206.2.102 10.206.2.101 2 u 586 1024 377 1.898 -6.212 52.072
*10.206.2.101 .LOCL. 1 u 1044 1024 377 0.985 -2.890 63.651
Here,* denotes the current External Time Source.In this case,the Synchronization is with the local clock on the host(refID is .LOCL. OR .LOCAL.).This is not allowed,since Local Clock is deemed as an
""Undisciplined Local Clock".In such cases,End Users should verify for a line as below in ntp.conf-
"server 127.127.1.0"
If the cluvfy/Installer detects this,then it throws the error PRVG-13602.
For complete details of the command and the output interpretation,Please refer to URL - https://pthree.org/2013/11/05/real-life-ntp/
Attention should be paid to the offset value in the ntpq -p output.cluvfy/Installer will fail if the offset is larger than 1000ms and the installation will abort.
Note - If there are no Time Servers available within the Environment,that can be used for Time Sync,then the End Users are free to pick any server from http://www.pool.ntp.org/zone/us
or any other zone that they belong to.
For example, something like the following could be added to the ntp.conf file
server 0.us.pool.ntp.org
server 1.us.pool.ntp.org
server 2.us.pool.ntp.org
server 3.us.pool.ntp.org
==================================
For above error /etc/resolve.conf is responsable
The /etc/resolv.conf file allows the DNS to translate user-friendly domain names into IP addresses.
The etc/resolv.conf file must be edited on each RAC node.
The /etc/resolv.conf file is used to point the node where the IP address and DNS matches the system-wide DNS server name.
With RAC, we edit the /etc/resolv.conf file on each RAC node and always make sure the file contains the following entries,
where the IP address and domain match those of your DNS server and the domain you have configured.
nameserver 192.168.1.1
search localdomain
Here is the format of an /etc/resolv.conf file:
search "same DNS domain name"
domain "same DNS local domain name"
Here is an example of an /etc/resolv.conf file:
cat /etc/resolv.conf
search "192.168.1.1"
domain "appsol"
nameserver "192.168.1.1"
Note that you can have up to three nameserver entries in /etc/resolv.conf.
For reference oracle document id : 2438647.1
Steps to make DNS Entry persistent in RedHat Enterprise Linux Server 7.7 and 7.8
- Edit the file /etc/NetworkManager/NetworkManager.conf and add the entry dns=none just after the [main] line in the file
Final output should be looking like :-
... [main] dns=none #plugins=ifcfg-rh,ibft ...
2. Save the file and Exit
3. Make DNS server entries according to your requirements into the /etc/resolv.conf file
nameserver 8.8.8.8 nameserver 8.8.4.4
4. Save the file and Exit
5. Reboot the server once and check if DNS entries are persist post reboot
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