Using RMAN to Migrate On-Premises Databases to DBaaS Databases

Purpose

This tutorial covers the RMAN method to convert and migrate on-premises Oracle Database 12c databases to an Oracle Database 12c DBaaS that run on different platforms.

Time to Complete

Approximately 30 minutes.

Introduction

In this tutorial, you learn how to convert the data files of an on-premises Oracle Database 12c PDB or PDB tablespaces to restore them into the Oracle Database 12c DBaaS database using various modes.

Prerequisites

Before starting this tutorial, it may be helpful to have followed the Signing Up for a Database Cloud Service, Connecting to a Database Cloud Service (DBaaS) Instance Through an SSH Tunnel and Creating a Database Cloud Service (DBaaS) Instance tutorials.

This section explains how to transport tablespaces of an on-premises  database that runs on one platform into the DBaaS database that runs on a different platform. The section therefore explains how to backup tablespaces of the on-premises database, convert the data files and restore them into the existing PDB1 PDB of the DBaaS ORCL CDB.

Backup the On-premises PDB Tablespaces

1. To backup the on-premises tablespaces of the PREM_PDB PDB in cross-platform tablespace transport mode, you must set the tablespaces to READ ONLY mode.
   
   
   
   
   
   
2. Retrieve the platform name of the DBaaS database. Connect to the DBaaS database.
   
   
   
   
3. Backup the TBS_1 and TBS_2 tablespaces of the on-premises PREM_PDB PDB.
   
   BACKUP TO PLATFORM 'Linux x86 64-bit'
      FORMAT '/u04/tbs_n.bck'
      DATAPUMP FORMAT '/bkp/test.dmp' TABLESPACE tbs_1, tbs_2;

   
   
   
   

Note: The TO PLATFORM clause converts the data files on the on-premises platform. When you will have transferred the files, they will be ready to be plugged into the DBaaS PDB.

Transfer the Files of the On-premises Platform to the DBaaS VM

Use SCP to transfer the backup set and dump file securely from the on-premises platform (/on-premises  directory) to the DBaaS VM (/DBaaS directory).

scp -i your_identify_file oracle@IP_address:/on-premise/dumpfile.dmp /DBaaS/dumpfile.dmp

      scp -i your_identify_file oracle@IP_address:/on-premise/backupset.bck /DBaaS/backupset.bck




Remark: The grayed out refer to the IP address of the source platform.


Restore the Files into the DBaaS PDB

1. Restore the TBS_1 and TBS_2 tablespaces of the on-premises PREM_PDB PDB into the DBaaS PDB1 PDB.
   
   
   
   RESTORE FOREIGN TABLESPACE tbs_1, tbs_2
      FORMAT '/u03/test_%U_%n.dbf' FROM BACKUPSET '/u03/tbs_n.bck'
      DUMP FILE FROM BACKUPSET '/u03/tbs_n.dmp' ;

   


2. Display the names of the data files of the transported tablespaces into the DBaaS PDB.
   
   


3. Set the transported tablespaces read write in the DBaaS PDB.
   
   


4. If you intend to work with the on-premises tablespaces, set them back to read write.
   
   


5. Display the names of the data files of the transported tablespaces from the on-premises PDB.
   
   

This section explains how to transport an on-premises database that runs on one platform into the DBaaS database that runs on a different platform. The section therefore explains how to backup the on-premises database, convert the data files and restore it into the existing DBaaS ORCL CDB.
Performing cross-platform data transport of one or more PDBs by using the CONVERT command is not supported. This is the reason why you use the BACKUP TO TRANSPORT or BACKUP FOR TRANSPORT RMAN command. Nevertheless the on-premises  platform and DBaaS  platform must use the same endian format.
The PDB needs to be in ARCHIVELOG mode which requires the on-premises CDB to be in ARCHIVELOG mode.

Unplug and Backup the On-premises PDB

1. Before transporting and converting data files of the PDB, the on-premises PDB must be unplugged to retrieve the structure of the PDB that will be recreated in the DBaaS CDB.
   
   
   
   
2. Retrieve the platform name of the DBaaS database. Connect to the DBaaS database.
   
   
   
   
3. Backup the on-premises PREM_PDB PDB. Connect to the CDB to backup the whole PDB.
   


BACKUP
   TO PLATFORM 'Linux x86 64-bit'
   FORMAT '/tmp/pdb_prem.bck'
   PLUGGABLE DATABASE prem_pdb;

   

Note: The TO PLATFORM clause converts the data files on the on-premises platform. When you will have transferred the files, they will be ready to be plugged into the DBaaS PDB.

Transfer the Files of the On-premises Platform to the DBaaS VM

Use SCP to transfer the backup set and the XML file securely from the on-premises platform (/on-premises  directory) to the DBaaS VM (/DBaaS directory).

  scp -i your_identify_file oracle@IP_address:/on-premise/backupset.bck /DBaaS/backupset.bck





Restore the Files into the DBaaS CDB and Plug the PDB

1. Restore the on-premises PREM_PDB PDB into the DBaaS ORCL CDB.
   
   
   
   RESTORE ALL FOREIGN DATAFILES
      FORMAT '/u01/test_%U_%n.dbf'
      FROM BACKUPSET '/u03/pdb_prem.bck';

   


2. Plug the on-premises PDB_PREM PDB whose data files are now converted and transferred to the DBaaS VM into the DBaaS ORCL CDB.
   
   • Unset the Oracle Managed Files (OMF).
     
     
     
   • Retrieve the names of the on-premises data files from the XML file in order to define them in the CREATE PLUGGABLE DATABASE as the source data files.
     
     
     
     
   • Execute the following statement to create the PDB_PREM PDB into the DBaaS ORCL CDB using the converted data files from the on-premises PDB_PREM PDB.
     
     
     
     
   Observe that the /u03/temp01.dbf tempfile was not included in the backup set. The creation of the new PDB will automatically create it.
   
   
   • Open the DBaaS PDB_PREM PDB.
     
     
     Notice that there are some warnings about memory settings. This will not impact your work in the PDB. You can change the parameters values later.


3. Retrieve the service name of the new DBaaS PDB.
   
   


4. Add the new service name in the tnsnames.ora file and reload the listener.
   
   
   
   


5. Display the data files of the new DBaaS PREM_PDB PDB.
   
   

You can convert and migrate on-premises non-CDBs and PDBs before migrating them into the DBaaS database that run on different platforms.

In this tutorial, you learned to:
• Transport tablespaces of an on-premises PDB that runs on one platform into the DBaaS CDB that runs on a different platform
• Transport a PDB of an on-premises CDB that runs on one platform into the DBaaS CDB that runs on a different platform

Resources

• For more detailed information about connecting to Oracle Database instances in the Oracle Database Cloud Service (DBaaS), see the documentation.
• To learn more about Oracle Database Cloud Service, visit the Database Cloud Service.
• For training on the Oracle Cloud platform-as-a-service (PaaS) Services, visit the Oracle Learning Library
• Look at these Oracle By Examples on working with the Oracle Database Cloud Service:
• Creating a Database Instance in the Oracle Database Cloud Service
• Connecting to a Database Instance in the Oracle Database Cloud Service
• Limitations During Migration From on-premises Databases to DBaaS Databases
• Exporting an on-premises PDB and Importing into the DBaaS Database
• Unplugging and Plugging non-CDBs and PDBs into DBaaS CDB
• Remote Cloning Method to Migrate on-premises Databases to the Cloud

Credits

• Lead Curriculum Developer: Dominique Jeunot
• Other Contributors: James Spiller