Oracle Checkpoint: Migrating On-Premises Oracle Databases to Exadata@AWS Using ZDM (Offline Migration)

As organizations modernize their database infrastructure, Oracle Database@AWS (Exadata Cloud Service) offers a powerful combination of Oracle performance with AWS scalability. One of the most reliable ways to move your on-premises Oracle database to this environment is by using Oracle Zero Downtime Migration (ZDM).

In this blog, we will walk through how to perform an offline migration using ZDM, which is ideal for databases where a downtime window is acceptable.

What is Oracle ZDM?

Oracle Zero Downtime Migration (ZDM) is Oracle’s recommended tool for migrating databases to Oracle Cloud, including Exadata Cloud at Customer and Exadata Database Service on AWS. It supports both online and offline migration methods.

Online Migration: Minimal downtime using Data Guard
Offline Migration: Uses RMAN backup/restore (focus of this blog)

When to Choose Offline Migration?

When downtime is acceptable
When network bandwidth is limited
When simplicity is preferred over continuous sync
For non-production or large batch migrations

Architecture Overview

The offline migration process involves:

Taking an RMAN backup of the source database
Transferring backup to Object Storage or NFS
Restoring the database on Exadata@AWS

Key Components:

Source Database (On-Premises)
ZDM Host (can be on-prem or cloud VM)
Target Exadata@AWS Environment
Backup Storage (OCI Object Storage / NFS / S3 via integration)

Prerequisites

Oracle ZDM installed on a Linux host
Passwordless SSH between ZDM host and source/target
Oracle Home configured on source and target
Database version supported by ZDM
Sufficient storage for RMAN backups
Network connectivity between environments

Step-by-Step Migration Process

1. Install and Configure ZDM

$ unzip zdm_install.zip
$ ./zdmsetup.sh install

Verify installation:

$ zdmcli -build

2. Prepare the Source Database

Ensure database is in ARCHIVELOG mode
Take a full RMAN backup
Validate backup integrity

RMAN> BACKUP DATABASE PLUS ARCHIVELOG;
RMAN> VALIDATE BACKUPSET;

3. Configure ZDM Response File

Create a response file defining migration parameters:

MIGRATION_METHOD=OFFLINE
SOURCE_DB_UNIQUE_NAME=onpremdb
TARGET_DB_UNIQUE_NAME=exadatadb
BACKUP_LOCATION=/backup_location
TARGET_NODE=exadata_target_host

4. Validate Migration Setup

Run a dry-run validation before actual migration:

$ zdmcli migrate database \
  -rsp response_file.rsp \
  -eval

This ensures all prerequisites are met.

5. Execute Migration

Start the offline migration:

$ zdmcli migrate database \
  -rsp response_file.rsp

ZDM will perform:

Backup transfer
Database restore on Exadata@AWS
Recovery and configuration

6. Post-Migration Tasks

Validate database functionality
Update application connection strings
Perform performance tuning
Take a fresh backup on target

Best Practices

Use compression for RMAN backups
Test migration in a staging environment first
Monitor logs using ZDM CLI
Ensure proper IAM and storage access (S3/OCI)

Common Challenges

Network bottlenecks during backup transfer
Incorrect SSH configuration
Version incompatibility
Insufficient storage on target

Conclusion

Offline migration using ZDM is a simple, reliable, and well-structured approach to move your on-premises Oracle databases to Exadata@AWS. While it requires downtime, it reduces complexity and provides a predictable migration path.

If your organization can afford a maintenance window, this method is often the fastest and safest way to modernize your database infrastructure.

Oracle Checkpoint

Tuesday, 5 May 2026

Migrating On-Premises Oracle Databases to Exadata@AWS Using ZDM (Offline Migration)