RMAN CDB Duplication While Skipping Selected PDBs

In large domain Oracle Multitenant (CDB/PDB) environments, it is often unnecessary—and inefficient—to duplicate all pluggable databases. RMAN provides the flexibility to duplicate only the required PDBs while skipping others, significantly reducing time, storage, and risk.

This article explains how to:

Duplicate a Container Database (CDB) from RMAN backup pieces
Skip selected Finance PDBs
Use ASM with Oracle Managed Files (OMF)
Create datafiles and redo logs automatically in +DATA and +RECO
Run the duplication in background using nohup

Scenario

Component	Name
Source CDB	FINCDB_PROD
Target CDB	FINCDB_DEV
Backup Location	`/backup_local/rman/FINCDB_19JAN2026`
ASM Disk Groups	`+DATA` (datafiles), `+RECO` (redo logs)
Skipped PDBs	`FIN_AP_PDB`, `FIN_AR_PDB`, `FIN_HR_PDB`
Required PDBs	`FIN_GL_PDB`, `FIN_FA_PDB`

Prerequisites

Valid RMAN full backup of source CDB
Target Oracle Home installed and patched
ASM disk groups +DATA and +RECO mounted
Adequate storage and permissions
Auxiliary instance not registered in CRS (for non-RAC)

Step 1: Create a Minimal Initialization Parameter File (PFILE)

Create a basic PFILE for the auxiliary database.


*.db_name='FINCDB_DEV'
*.enable_pluggable_database=true
*.memory_target=16G
*.processes=2000
*.db_create_file_dest='+DATA'
*.db_create_online_log_dest_1='+RECO'
*.compatible='19.0.0'

Save as:


/tmp/initFINCDB_DEV.ora

Step 2: Start Auxiliary Database in NOMOUNT Mode


SQL> STARTUP NOMOUNT PFILE='/tmp/initFINCDB_DEV.ora';

Confirm status:


SQL> SELECT status FROM v$instance;

Step 3: RMAN Duplicate Command (Skip Finance PDBs)

Create the RMAN command file:


vi FINCDB_DEV_duplicate.cmd


RUN {
  ALLOCATE AUXILIARY CHANNEL c1  DEVICE TYPE DISK;
  ALLOCATE AUXILIARY CHANNEL c2  DEVICE TYPE DISK;
  ALLOCATE AUXILIARY CHANNEL c3  DEVICE TYPE DISK;
  ALLOCATE AUXILIARY CHANNEL c4  DEVICE TYPE DISK;
  ALLOCATE AUXILIARY CHANNEL c5  DEVICE TYPE DISK;
  ALLOCATE AUXILIARY CHANNEL c6  DEVICE TYPE DISK;
  ALLOCATE AUXILIARY CHANNEL c7  DEVICE TYPE DISK;
  ALLOCATE AUXILIARY CHANNEL c8  DEVICE TYPE DISK;

  DUPLICATE DATABASE TO FINCDB_DEV
    BACKUP LOCATION '/backup_local/rman/FINCDB_19JAN2026'
    SKIP PLUGGABLE DATABASE FIN_AP_PDB,
                             FIN_AR_PDB,
                             FIN_HR_PDB
    NOFILENAMECHECK;
}

Step 4: Run Duplication in Background


nohup rman auxiliary / \
cmdfile=FINCDB_DEV_duplicate.cmd \
log=FINCDB_DEV_duplicate.log &

Monitor progress:


tail -f FINCDB_DEV_duplicate.log

Step 5: ASM File Placement (Automatic)

Because the following parameters are set:


db_create_file_dest=+DATA
db_create_online_log_dest_1=+RECO

Oracle automatically:

Creates datafiles and tempfiles in +DATA
Creates online redo logs in +RECO
Uses OMF naming (no manual file mapping)

Step 6: Post-Duplicate Validation

Check CDB Status


SELECT name, open_mode FROM v$database;

Verify PDBs


SHOW PDBS;

Expected:

Required PDBs → OPEN

Skipped PDBs → NOT PRESENT

Validate ASM Locations


SELECT name FROM v$datafile;
SELECT member FROM v$logfile;

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RMAN CDB Duplication While Skipping Selected PDBs