4.11.1 Change the DNS Server Address on the Database Server

This procedure describes how to change the DNS server address on the database servers.

1. If you are using Oracle Exadata System Software 20.1.0 or later, use ipconf with the -update and -dns options to modify the DNS settings.
   1. Log in to the database server as the root user.
   2. Check to make sure there are no configuration issues with the new settings.

      Use the following command, where IP_addr_list is a comma-separate list of IP addresses for the DNS servers. If you also want to check the DNS servers for ILOM, then include the -ilom-dns parameter and replace ILOM_DNS_list with a comma-separate list of up to 3 IP addresses for the DNS servers. Including the -dry parameter means the settings are checked, but not applied.

      # ipconf -update -dns IP_addr_list [-ilom-dns ILOM_DNS_list] -dry

   3. Update the DNS settings using the following ipconf command:

      In the following command, IP_addr_list is a comma-separate list of IP addresses for the DNS servers. If you also want to change the DNS servers for ILOM, then include the -ilom-dns parameter and replace ILOM_DNS_list with a comma-separate list of up to 3 IP addresses for the DNS servers. Include the -force parameter to force the update, bypassing all checks.

      # ipconf -update -dns IP_addr_list [-ilom-dns ILOM_DNS_list] [-force]

      Here is an example of the command and its output.

      [root@dbm03adm02]# ipconf -update -dns 10.31.138.25,10.231.225.65
      [Info]: ipconf command line: ipconf -update -dns 10.31.138.25,10.231.225.65
      Logging started to /var/log/cellos/ipconf.log
      [Info]: Updating dns/ntp
      [Info]: Backup existing cell configuration file /opt/oracle.cellos/cell.conf 
      to /var/log/exadatatmp/cell.conf_2020_01_13-17_59_44
      [Info]: Custom changes have been detected in /etc/resolv.conf
      [Info]: Original file /etc/resolv.conf will be saved in /etc/resolv.conf.backupbyExadata
      [Done]: Update cell configuration file /opt/oracle.cellos/cell.conf OK
      

   4. Repeat these steps for each database server.
2. If you are using Oracle Exadata System Software 19.3.x or earlier, then use the following steps to modify the DNS servers.
   1. Log in to the database server as the root user.
   2. Edit the /etc/resolv.conf file.
      Set the DNS server and domain name using an editor such as vi. There should be a name server line for each DNS server.

      search        example.com
      nameserver    10.7.7.3
      

   3. Set the DNS server in the server ILOM.

      ipmitool sunoem cli 'set /SP/clients/dns nameserver=dns_ip'
      

      In the preceding command, dns_ip is the IP address of the DNS server. If there is more than one DNS server, then enter a comma-separated list such as set /SP/clients/dns nameserver=dns_ip1,dns_ip2,dns_ip3.

   4. Repeat these steps for each database server.