ZDM (Zero Downtime Migration) 



Different migration types

* Offline/Online 

* Physical (RMAN/DataGuard) / Logical (GG/ Datapump) 

* Direct/Indirect Connection 


Target DB: 

* Base Database Service (BaseDB) -Logical/Physical Migration 

* Exadata Database Service (ExaDB-D) -Logical/Physical Migration 

* Exadata Cloud@Customer (ExaDB-C@C) -Logical/Physical Migration 

* Exadata On-Prem -Logical/Physical Migration 

* Exadata Cloud@Customer (ADB-C@C) -Logical Migration

* Autonomous Database Shared (ADB-S) -Logical Migration

* Autonomous Database Dedicated (ADB-D) -Logical Migration

 

Logical/Physical Migration 

* OCI Database Migration (DMS) -Logical Migration Only

* Zero Downtime Migration (ZDM) -Software, Logical/Phyiscal Migration

* Native tools -DataGuard, DataPump, RMAN, PDB-Unplug/plug, Remote Clone, Relocate, Golden Gate, SQL*Loader, DBLink CTAS, 

DBMS_CLOUD, Rest API, SQLcl, OEM etc)

RMAN - Physical Offline

DataGuard - Physical Online 

Data pump (backup location or dblink) - Logical Offline 

Data Pump & Golden Gate  (backup location or dblink) - Logical Online 


Install Oracle Zero Downtime Migration (ZDM) in Linux:

1. Dedicated Linux Host

2. Storage Space: Ensure at least 100 GB

3. Network Connectivity: The ZDM service host must have SSH access and port 1521 access to both the source and target database servers. 

4. User and Directories:

User: zdmuser

Group: zdm

Directory: /home/zdmuser/zdminstall, /home/zdmuser/zdmhome, /home/zdmuser/zdmbase 

Set appropriate ownership and permissions

5. OS Packages

yum install oraclelinux-developer-release-el8 libnsl perl unzip glibc-devel expect libaio ncurses-compat-libs ncurses-devel numactl-libs openssl mlocate bind-utils -y

6. ZDM Software Installation:

cd zdm_download_directory

unzip zdmversion.zip

./zdminstall.sh setup oraclehome=/u01/app/zdmhome oraclebase=/u01/app/zdmbase ziploc=/u01/app/oracle/zdm/shiphome/zdm_home.zip

$ZDMHOME/bin/zdmcli -build

zdmservice status | start | stop 

7. Prepare for Migration:

Response File: Create or prefill a response file (e.g., physical_online.rsp) containing information about the source database, target database, and migration parameters.

Authentication Token (for OCI targets): If migrating to OCI, generate an authentication token for the OCI user and store it securely.

8. Perform Migration:

Execute Migration Command: Use zdmcli migrate database with the response file and other arguments to initiate the migration.

zdmcli query job -jobid 54 


CPAT: Cloud Premigration Advisor Tool 


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