Migrating Oracle workloads from on-premises environments to Oracle Autonomous Database on Azure (ADB@Azure) can be achieved with near-zero downtime using Oracle Zero Downtime Migration (ZDM) and Oracle GoldenGate (OGG).

This guide provides a streamlined step-by-step approach covering source preparation, GoldenGate setup, ZDM configuration, and migration execution.

1. Architecture Overview

The migration setup consists of:

  • Source Database (On-Prem Oracle DB)
  • GoldenGate Hub VM
  • ZDM Server
  • ADB@Azure Target Database
  • NFS Storage for Data Pump transfer

Migration Flow

  1. Prepare source database
  2. Configure GoldenGate replication
  3. Prepare ADB@Azure target
  4. Configure GoldenGate VM
  5. Configure ZDM server
  6. Run ZDM evaluation
  7. Execute online logical migration
  8. Monitor GoldenGate lag
  9. Perform cutover

2. Source Database Preparation

ZDM Requirements

Create SSH Connectivity

  • Add Oracle user to required OS group
  • Generate SSH key pair for Oracle user
  • Copy private key to ZDM server
ssh-keygen -t rsa

Example private key:

id_rsa

Database Parameter Configuration

Run the following SQL statements:

alter system set PGA_AGGREGATE_LIMIT=0 scope=both sid='*';
grant exempt access policy to SYSTEM;
alter system set streams_pool_size=2G scope=both;
alter system set global_names=false;

3. Enable GoldenGate Requirements

Enable ARCHIVELOG Mode

shutdown immediate;
startup mount;
alter database archivelog;
alter database open;
select log_mode from v$database;

Enable FORCE LOGGING

alter database force logging;
select force_logging from v$database;

Enable Supplemental Logging

select minimal from dba_supplemental_logging;
alter database add supplemental log data;
select minimal from dba_supplemental_logging;

Enable GoldenGate Replication

alter system set ENABLE_GOLDENGATE_REPLICATION=TRUE scope=both;

Create GGADMIN User

create user ggadmin identified by ******** default tablespace users temporary tablespace temp;

grant connect, resource to ggadmin;
grant unlimited tablespace to ggadmin;
alter user ggadmin quota 10G on users;

grant select any dictionary to ggadmin;
grant create view to ggadmin;
grant execute on dbms_lock to ggadmin;

exec dbms_goldengate_auth.GRANT_ADMIN_PRIVILEGE('ggadmin');

grant execute on DBMS_SCHEDULER to ggadmin;
grant select any sequence to ggadmin;
grant alter system to ggadmin;
grant alter database to ggadmin;
grant logmining to ggadmin;

4. Target ADB@Azure Preparation

Recommended Actions

  • Disable auto maintenance jobs
  • Scale up ECPU temporarily for migration
  • Create GGADMIN user
  • Apply GoldenGate grants

Example:

CREATE USER ggadmin IDENTIFIED BY <password>;

GRANT CONNECT, RESOURCE TO ggadmin;
GRANT CREATE SESSION, ALTER SESSION TO ggadmin;
GRANT SELECT ANY DICTIONARY TO ggadmin;
GRANT FLASHBACK ANY TABLE TO ggadmin;
GRANT LOGMINING TO ggadmin;

5. GoldenGate VM Setup

Infrastructure Requirements

  • NFS mounted
  • Sufficient CPU / Memory / Disk
  • Docker Engine installed
  • GoldenGate container image downloaded from OCI Marketplace

Install Docker

Since internet access may be restricted in secured environments:

  1. Download Docker RPM manually
  2. Upload RPM to VM
  3. Install RPM
yum install docker-engine.rpm

Start Docker:

sudo systemctl enable --now docker
sudo systemctl status docker
docker info

Load GoldenGate Docker Image

docker load < ./ora23ai-2113000.tar
docker image list

Disable IPv6 in NGINX (Required in Restricted Environments)

Inside container:

docker run -it --entrypoint=/bin/bash <goldengate-image>

1: docker run -it --entrypoint=/bin/bash <your-goldengate-image>  
  
     docker run -it --entrypoint=/bin/bash docker.io/localhost/oracle/goldengate:23.9.0.25.07
	 
  2: Locate and edit the relevant NGINX configuration file: 
      vi /etc/nginx/conf.d/ogg.conf
  3: In the `server` block for HTTPS (port 443), comment out or remove lines that specify IPv6 bindings, such as:  
     ```
     # listen [::]:443 ssl;  
     ```
     Leave the IPv4 equivalent intact (e.g., `listen 443 ssl;`). If there's a similar line for port 80, handle it the same way if needed.
  4: Exit the container
  5: For persistence across container restarts (recommended), extract the modified config file using `docker cp <container-id>:/etc/nginx/conf.d/ogg.conf ./local-ogg.conf`, then run the container with a volume mount:  
   (ex : :docker cp 631d0f4a2e72://etc/nginx/nginx.conf /appdata/goldengate/nginx_new.conf

nohup docker run --name ogg2390 -p 443:443 -v /appdata/goldengate/nginx_new.conf:/etc/nginx/nginx.conf docker.io/localhost/oracle/goldengate:23.9.0.25.07 &

Edit:

vi /etc/nginx/conf.d/ogg.conf

Comment IPv6 entries:

# listen [::]:443 ssl;

Persist configuration using volume mounts.

Change Docker Root Directory(Optional)

By default Docker uses /var/lib/docker, which may have limited storage.

Move Docker Data

systemctl stop docker
rsync -aP /var/lib/docker /appdata/gg_docker

Update:

vi /etc/docker/daemon.json

{
  "data-root":"/appdata/gg_docker/docker"
}

Restart Docker:

systemctl start docker
docker info | grep "Docker Root Dir"

6. Configure ADB Wallet inside GoldenGate

Copy wallet ZIP into container:

mv Wallet_xxx.zip /home/ogg/

Unzip wallet:

mkdir /u02/Deployment/etc/adb
unzip Wallet_xxx.zip

Update sqlnet.ora:

DIRECTORY="/u02/Deployment/etc/adb"

Update /etc/hosts with:

  • ADB hostname
  • Source DB hostname
  • ZDM server hostname

7. ZDM Server Setup

Prerequisites

  • Create zdmuser
  • Install ZDM 21c or later
  • Mount NFS storage
  • Configure environment variables
export ZDMHOME=/home/zdmuser/zdmhome
export ZDMBASE=/home/zdmuser/zdmbase

Create Migration Workspace

mkdir /home/zdmuser/logical_online_adb_nfs

Create response file:

vi logical_online_adb_nfs.rsp

8. Configure ZDM Response File

Key parameters:

MIGRATION_METHOD=ONLINE_LOGICAL
DATA_TRANSFER_MEDIUM=NFS

Data Pump Configuration

DATAPUMPSETTINGS_JOBMODE=SCHEMA
DATAPUMPSETTINGS_DATAPUMPPARAMETERS_EXPORTPARALLELISMDEGREE=12
DATAPUMPSETTINGS_DATAPUMPPARAMETERS_IMPORTPARALLELISMDEGREE=18

Source Database

SOURCEDATABASE_CONNECTIONDETAILS_HOST=<source-host>
SOURCEDATABASE_ADMINUSERNAME=SYSTEM
SOURCEDATABASE_GGADMINUSERNAME=ggadmin

Target Database

TARGETDATABASE_ADMINUSERNAME=ADMIN
TARGETDATABASE_GGADMINUSERNAME=ggadmin

GoldenGate Hub

GOLDENGATEHUB_URL=https://<goldengate-vm-ip>
GOLDENGATEHUB_ALLOWSELFSIGNEDCERTIFICATE=TRUE

Wallet Configuration

TARGETDATABASE_CONNECTIONDETAILS_TLSDETAILS_CREDENTIALSLOCATION=/home/zdmuser/wallet

9. Run ZDM Evaluation

Before executing migration, validate configuration.

$ZDMHOME/bin/zdmcli migrate database \
-rsp logical_online_adb_nfs.rsp \
-skipadvisor \
-sourcenode <source-node> \
-sourcesid <source-sid> \
-srcauth dbuser \
-srcarg1 user:oracle \
-srcarg2 identity_file:/path/id_rsa \
-eval

10. Execute Online Migration

Once evaluation succeeds:

$ZDMHOME/bin/zdmcli migrate database \
-rsp logical_online_adb_nfs.rsp \
-skipadvisor \
-sourcenode <source-node> \
-sourcesid <source-sid> \
-srcauth dbuser \
-srcarg1 user:oracle \
-srcarg2 identity_file:/path/id_rsa \
-pauseafter ZDM_MONITOR_GG_LAG

11. Migration Activities Automated by ZDM

ZDM automatically performs:

  • GoldenGate Extract creation
  • Replicat configuration
  • Data Pump export/import
  • Initial load
  • Continuous replication
  • Lag monitoring
  • Cutover orchestration

12. Monitor Migration Progress

Query migration jobs:

$ZDMHOME/bin/zdmcli query job -jobid <jobid>

Monitor:

  • GoldenGate lag
  • Extract status
  • Replicat status
  • Data Pump completion
  • Target synchronization

13. Best Practices

Performance Recommendations

  • Scale up ADB ECPU during migration
  • Use high parallelism for Data Pump
  • Ensure adequate disk space for trail files
  • Keep NFS throughput optimized

Operational Recommendations

  • Validate supplemental logging before start
  • Test wallet connectivity independently
  • Monitor GoldenGate lag continuously
  • Keep rollback strategy ready until cutover

Conclusion

Using Oracle ZDM with GoldenGate provides a robust and near-zero downtime approach for migrating on-premises Oracle databases to ADB@Azure.

The combination of:

  • ZDM automation
  • GoldenGate replication
  • Data Pump parallelism
  • Autonomous Database scalability

ensures a reliable, scalable, and operationally efficient migration process.

The above steps are not limited to Oracle ADB@Azure but can also be used in other multicloud environments like AWS and GCP.