Oracle EBS DR Testing Issues — Practical Fixes

When setting up Disaster Recovery (DR) for Oracle E-Business Suite (EBS) 12.2, the goal is always simple — reduce complexity during failover.

In our case, we followed a logical hostname approach, so we didn’t have to perform node cleaning or heavy reconfiguration. The plan was straightforward:

• Run AutoConfig
• Start services
• Bring up DR quickly

But in reality, we hit a few issues that required careful fixes. This post shares what went wrong and how we resolved it during our DR Drill activity.

Setup Overview

Below data is sample information and not actual data to simulate the same and avoid sharing any customer sensitive data

• Primary DB Server: ebsdbp01.oratest.com
• DR DB Server: ebsdbdr01.oratest.com
• Database Name: EBSCDB

Oracle Homes:

• Primary: /u01/oracle/19.0.0
• DR: /u01/oracle/19c

Issue 1: AutoConfig Failed Due to Different DB Home

Even though the logical hostnames were aligned, AutoConfig failed on DR.

Root Cause

EBS expects consistent paths across environments when using logical hostname. The difference in DB Home caused configuration mismatches. All teh errors are related to database connectivity and tns gen files as the locaiton does not exist to which teh context file is pointg.

Fix

We created a soft link on DR to match the primary DB Home and This resolved the initial AutoConfig failures. While Soft link is not recommended, due to time limitations we proceeded with this activity

ln -s /u01/oracle/19c /u01/oracle/19.0.0

Recommendation: Move oracle home to new directory /u01/oracle.19.0.0 and perform database home relinking. Planned to perform this post DR Trial.

Issue 2: Missing NLS Data (9i Dependency)

After fixing the DB Home path, AutoConfig still failed with errors like:

Looking for the directory:
/u01/oracle/product/19C/nls/data/9idata

Directory does not exist

Root Cause

Oracle EBS still expects certain legacy NLS data (from older versions like 9i), even on newer databases.

Fix

• During the DR setup, the required configurations steps are not completed.
• Copied the required NLS data from Primary DB Home and Ensured it existed under:

$ORACLE_HOME/nls/data

Issue 2: ORA-28547 (Oracle Net Configuration Issue)

We also encountered:

ORA-28547: connection to server failed, probable Oracle Net admin error

Root Cause

This was linked to environment and path inconsistencies, especially:

• Incorrect NLS paths
• Hardcoded environment variables
• Misalignment between PRIMARY and DR configurations

Fix

We made two key corrections:

1. Updated ORA_NLS10

In the environment file EBSCDB_testdb01.envchanged from

ORA_NLS10=/u01/oracle/19.0.0/nls/data/...
to
ORA_NLS10=$ORACLE_HOME/nls/data

2. Ensured Consistent Oracle Net Setup

• Verified tnsnames.ora and listener.ora
• Ensured paths aligned with the updated ORACLE_HOME
• Revalidated connectivity after changes

Key Takeaways

• Path consistency is critical in Oracle EBS environments
• Even small differences like DB Home can break AutoConfig
• EBS still depends on older components like 9i NLS data
• Avoid hardcoding paths — always use variables like $ORACLE_HOME
• DR is not just about replication — it’s about configuration alignment