Duplicating a Database with the RMAN Duplicate Command

Introduction

There are four patterns for database duplication.

The available options depend on the system requirements.

In this example, we use pattern 4: “Backup-based duplication without connecting to target or recovery catalog”.

1. Active duplication

   Duplicates directly from an open or mounted database.

2. Backup-based duplication without target connection

   RMAN creates duplicate files from existing RMAN backups and copies.

   This form requires a connection to the auxiliary instance and the recovery catalog.

3. Backup-based duplication with target connection

   Creates duplicate files from existing RMAN backups and copies.

4. Backup-based duplication without connecting to target or recovery catalog

   Creates duplicate files from RMAN backups and copies placed at the location specified by BACKUP LOCATION.

Note that restore and recovery from an RMAN backup is also a form of database duplication, but it is not covered in this example.

Environment Configuration

This procedure duplicates within the same host.

Take an RMAN backup on the source:

rman target /
run {
  BACKUP INCREMENTAL LEVEL 0 DATABASE FORMAT '/home/oracle/rman/db121s/full_%d_%T_%U' SPFILE PLUS ARCHIVELOG FORMAT '/home/oracle/rman/db121s/ARCH_%d_%T_%U';
  BACKUP AS COPY CURRENT CONTROLFILE FORMAT '/home/oracle/rman/db121s/CNT_%d_%T_%U.ctl';
}

Clean Up Destination

rm -rf /u01/app/oracle/oradata/DB121T/*

Create Destination Parameter File

Connect to the source database and create an editable pfile from the spfile.

. /home/oracle/.oraenv_db121s
sqlplus / as sysdba
create pfile='/tmp/initdb121t.ora' from spfile;
exit

Edit Destination Parameter File

Change values that depend on the source to destination-specific values. (e.g., change db_name from “db121s” to “db121t”)

vi /tmp/initdb121t.ora

Change the following parameter values:
- *.cluster_database     : false
- *.control_files        : /u01/app/oracle/oradata/db121t
- *.db_name              : db121t
- *.db_unique_name       : db121t
- *.dispatchers          : (PROTOCOL=TCP) (SERVICE=db121tXDB)

Add the following parameters:
*.DB_FILE_NAME_CONVERT='/u01/app/oracle/oradata/DB121S/datafile/','/u01/app/oracle/oradata/DB121T/datafile/'
*.LOG_FILE_NAME_CONVERT='/u01/app/oracle/oradata/DB121S/onlinelog/','/u01/app/oracle/oradata/DB121T/onlinelog'

Start Auxiliary Instance

. /home/oracle/.oraenv_db121t
sqlplus / as sysdba
startup nomount pfile='/tmp/initdb121t.ora'

Create spfile

create spfile = '/u01/app/oracle/product/12.1.0.2/dbhome_2/dbs/spfiledb121t.ora' from pfile='/tmp/initdb121t.ora';
exit

Execute Duplicate Command

rman auxiliary /
run {
duplicate database to db121t backup location '/home/oracle/rman/db121s';
}

For details on the RMAN duplicate command, please refer to the manual:

Oracle® Database Backup and Recovery Reference 12c Release 1 (12.1)

https://docs.oracle.com/cd/E57425_01/121/RCMRF/rcmsynta020.htm

DUPLICATE