How to Overcome Oracle 19c RAC Installation Issues: Network, IPv6, and Patch Permissions

When Oracle 19c was released, many customers began migrating from older versions such as 11g. The author describes a recent on‑site installation of Oracle 19c RAC (version 19.7) on Red Hat 7.6, highlighting several pitfalls and their solutions.

Environment

Operating System: Redhat 7.6

Oracle Database version: 19.7

RAC enabled: Yes

Root.sh Failure – Missing IPv6 Loopback

During the root.sh execution, step 18 failed with the error that ora.qosmserver could not start. The log showed only that the service failed to open, providing no useful details.

Research revealed a known issue where the IPv6 loopback address ::1/128 is not configured. The /etc/hosts file had the line containing ::1 commented out. Uncommenting that line and re‑running root.sh allowed the installation to proceed successfully.

Patch Installation – File Permission Problem

After the base installation, a patch was applied. The process failed with an error pointing to /oracle/app/oraInventory/ContentsXML/oui-patch.xml lacking write permission for the grid user group.

Investigation showed the file was generated during the patch upgrade in the DB HOME, but the default permissions prevented the grid user from writing to it. The fix was to immediately set the file permissions to 664 (rw‑rw‑r--) after the file appeared, after which the patch applied without further issues.

Additional CRS Alerts

CRS alert logs reported missing files on some nodes. After confirming the cluster and database were otherwise healthy, the author concluded these messages were from optional features and could be safely ignored.

Configuring IPv6 for Oracle RAC

The customer decided to migrate the network to IPv6. Two common methods to verify IPv6 is enabled on Linux were demonstrated:

Check network interface attributes with ifconfig -a – presence of an inet6 line indicates IPv6 is active.

Inspect loaded kernel modules using lsmod | grep ipv6.

After confirming IPv6 support, the author added custom IPv6 addresses to the network interface configuration file, defining a primary and a backup address, and then restarted the network.

Connectivity was verified with ping6 (or ping -6).

Updating Listener Configuration

The listener.ora file was edited to include an IPv6 address and port, ensuring the IPv6 listener uses a different port from the IPv4 listener:

LISTENER=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=IPC)(KEY=LISTENER))
  (ADDRESS=(PROTOCOL=TCP)(HOST=2020:db8:1000::200)(PORT=1601)(IP=FIRST)))
)

After restarting the listener, the new configuration was confirmed via the listener status output.

Testing the IPv6 Connection

A TNS connection string incorporating the IPv6 address was created and successfully used to connect to the database, confirming that the IPv6 network setup was complete.

Conclusion

The experience shows that while Oracle database installations are becoming more automated in cloud environments, hands‑on knowledge of OS‑level networking, file permissions, and configuration files remains essential for troubleshooting complex RAC deployments.