Database Duplication from Recovery Appliance

If you need to duplicate a protected database to create a standby database or to clone a protected database to a target host, you can do so by connecting to the Recovery Appliance catalog and using backup-based duplication. By using the catalog, there is no need to connect to the source database. Creating a standby database or a clone both involve running the RMAN DUPLICATE command.

Note:

DUPLICATE is the recommended method to create a clone database for standby database, development, or testing purposes, because a new DBID is created for the clone database.

If the protected database must be restored to a new host following the RMAN restore and recover to a new host procedure that keeps the same DBID, you must disconnect from the catalog before performing OPEN RESETLOGS or use SQL Plus to open the database.

See Also:

Restoring a Database to a New Host
Oracle Database Backup and Recovery User’s Guide for additional information about duplicating databases
Oracle Database Backup and Recovery Reference for the syntax of the DUPLICATE command

Creating a Standby Database for a Protected Database

When you create a standby database from Recovery Appliance, you connect to the standby (auxiliary instance) and to the Recovery Appliance catalog, and run the RMAN DUPLICATE command with the FOR STANDBY option.

Note: Because the primary database is already registered with the Recovery Appliance catalog, you should not register the standby database with the Recovery Appliance catalog.

To create a standby database for a protected database:

On the target host, prepare the auxiliary instance by performing the following tasks:
- Create the directories in which the standby database files will be stored.
- Create an initialization parameter file for the auxiliary instance.
  
  The mandatory parameters are DB_NAME and DB_CREATE_FILE_DEST.
- Create a password file for the auxiliary database. This password file will be overwritten during the duplicate operation in step 3.
- Establish Oracle Net connectivity between the protected database and the auxiliary instance.
- Start the auxiliary instance in NOMOUNT mode.
Start RMAN and connect as CATALOG to the Recovery Appliance catalog and as AUXILIARY to the auxiliary instance.

In the following example, ra_rman_user is the Recovery Appliance user that the protected database my_ptdb uses to authenticate with the Recovery Appliance. ra1 is the net service name of the target Recovery Appliance that is configured in the Oracle wallet. stdby is the net service name of the auxiliary instance.
```
%rman
RMAN> CONNECT CATALOG ra_rman_user@ra1;
RMAN> CONNECT AUXILIARY "sys@stdby AS SYSDBA";
```

Create the standby database using the DUPLICATE command. Configure one or more auxiliary channels that correspond to the Recovery Appliance backup module.

The following example configures three auxiliary channels and creates a standby database for the protected database my_ptdb .

RUN
{
  ALLOCATE AUXILIARY CHANNEL c1 DEVICE TYPE sbt_tape
  PARMS='SBT_LIBRARY=/u01/oracle/product/12.1.0.2/dbhome_1/lib/libra.so,
  ENV=(RA_WALLET=location=file:/u01/oracle/product/12.1.0.2/dbhome_1/dbs/ra
  credential_alias=ra-scan:1521/zdlra5:dedicated)' FORMAT'%U_%d';
  ALLOCATE AUXILIARY CHANNEL c2 DEVICE TYPE sbt_tape
  PARMS='SBT_LIBRARY=/u01/oracle/product/12.1.0.2/dbhome_1/lib/libra.so,
  ENV=(RA_WALLET=location=file:/u01/oracle/product/12.1.0.2/dbhome_1/dbs/ra
  credential_alias=ra-scan:1521/zdlra5:dedicated)' FORMAT'%U_%d';
  ALLOCATE AUXILIARY CHANNEL c3 DEVICE TYPE sbt_tape
  PARMS='SBT_LIBRARY=/u01/oracle/product/12.1.0.2/dbhome_1/lib/libra.so,
  ENV=(RA_WALLET=location=file:/u01/oracle/product/12.1.0.2/dbhome_1/dbs/ra
  credential_alias=ra-scan:1521/zdlra5:dedicated)' FORMAT'%U_%d';
  DUPLICATE DATABASE my_ptdb FOR STANDBY DORECOVER;
}

Cloning a Protected Database

You can clone a protected database to a target host by using backup-based duplication. The Oracle-recommended method, covered in this section, connects to the Recovery Appliance catalog. By using a catalog for the duplicate operation, a connection to the source database is not required.

The example that follows represents the Oracle best practice for cloning a protected database and includes a sample script that you can customize for your scenario.

This example assumes the following:

backups of the target database exist on the Recovery Appliance and are available to the auxiliary instance
RMAN connection from the auxiliary database to the Recovery Appliance that contains metadata and backups for the target database is available
both source and duplicate database use Oracle Managed Files (OMF)
operating system used is Linux or UNIX
the audit directory is created on the auxiliary database host
prerequisites for backup-based duplication are met

The script provided in this example performs the following tasks:

drops an existing auxiliary database
backs up the target database
creates a dummy auxiliary instance and opens it in NOMOUNT mode
duplicates the target database using the target database backups and metadata available on the Recovery Appliance

The duplicate database control file is stored as +REDO/ORACLE_SID/CONTROLFILE/cf3.ctl and the data files are stored in the +DATA directory.
verifies that the required objects are created in the duplicate database

To clone a protected database using backup-based duplication without a target connection:

Create a parameter file (pfile) for the auxiliary instance. The pfile contains only the DB_NAME initialization parameter which is set to the SID of the duplicate database.

The following pfile, called init_dup.ora and located in the /home/oracle directory, sets the DB_NAME parameter. Replace dup_db with the SID of your duplicate database:
```
*.db_name = 'dup_db'
```

Use a text editor and create a Shell script (called dup_db.sh in this example) with the contents shown below and with the following modifications:

Replace the value of the ORACLE_HOME variable with the Oracle home directory of your auxiliary instance.
Replace the value of the logdir variable with the directory in which you want to store log files.
Replace the following placeholders (shown in Italics) with values appropriate to your duplication scenario:

dup_db: system identifier (SID) and service name of the auxiliary instance

tgt_db: SID and service name of the target database

sys_pswd: password for the SYS user of the target database

vpc_user: name of the VPC user

vpc_user_pswd: password for the VPC user vpc_user

ra_scan: Single Client Access Name (SCAN) of the Recovery Appliance

ra_servicename: service name of the Recovery Appliance metadata database

system_pswd: password for the SYSTEM user in the target database
If you want to store the duplicate database control file using a name and location that is different from +REDO/ORACLE_SID/CONTROLFILE/cf3.ctl, then replace the value of control_files in the dup_aux_db function with a value that is appropriate for your duplication scenario.
If you want to store the duplicate data files in a directory that is different from +DATA, then replace the value of db_create_file_dest in the dup_aux_db function with a value that is appropriate for your duplication scenario.

#!/bin/bash
export ORACLE_HOME=/u01/app/oracle/product/11.2.0.4/dbhome_2
export ORACLE_BASE=/uo1/app/oracle
export ORACLE_SID=dup_db
export PATH=$PATH:$HOME/bin:$ORACLE_HOME/bin:$ORACLE_HOME/Opatch
export LD_LIBRARY_PATH=$ORACLE_HOME/lib:$ORACLE_HOME/rdbms/lib:/lib:/usr/lib;
export LD_LIBRARY_PATH
export logdir=/home/oracle/log
export dt='date +%y%m%d%H%M%S'
export NLS_DATE_FORMAT='DD-MM-YYYY HH24:MI:SS'

function drop_aux_db {
export ORACLE_SID=dup_db
$ORACLE_HOME/bin/sqlplus -s '/ as sysdba' <<EOF2
set pagesize 999 linesize 999 heading off feedback off
select name, open_mode from v$database;
shutdown immediate;
startup mount exclusive restrict;
drop database;
exit;
EOF2
}

echo "Backup the target database"
function backup_source_db {
$ORACLE_HOME/bin/rman target sys/sys_pswd@tgt_db catalog
vpc_user/vpc_user_pswd@ra_scan:1521/ra_serivcename:dedicated <<EOF
RUN {
backup as backupset cumulative incremental level 1 database include current
controlfile plus archivelog not backed up delete input;}
exit;
EOF
}

sleep 120

echo "List the backup of the target database"
function check_source_db_backup {
$ORACLE_HOME/bin/rman target sys/sys_pswd@tgt_db catalog vpc_user/vpc_user_pswd@ra_scan:1521/ra_serivcename:dedicated <<EOF
LIST BACKUP OF DATABASE COMPLETED AFTER '(SYSDATE-1/24)';
EOF
}

echo "Start the auxiliary database in FORCE NOMOUNT mode"
function nomount_aux_db {
export ORACLE_SID=dup_db
$ORACLE_HOME/bin/rman target / <<EOF2
startup force nomount pfile='/home/oracle/init_dup.ora';
exit;
EOF2
}

echo "Duplicate the target database"
function dup_aux_db {
export ORACLE_SID=dup_db
$ORACLE_HOME/bin/rman catalog vpc_user/vpc_user_pswd@ra_scan:1521/ra_serivcename:dedicated AUXILIARY /
<<EOF
duplicate database tgt_db to dup_db spfile
set control_files '+REDO/${ORACLE_SID}/CONTROLFILE/cf3.ctl'
set db_create_file_dest '+DATA/' ;
exit;
EOF
}

echo "Check schema objects on the target"
function check_source_db {
$ORACLE_HOME/bin/sqlplus -s system/system_pswd@tgt_db <<EOF2
set pagesize 999 linesize 999 heading off feedback off
select name, open_mode from v$database;
select table_name, num_rows from dba_tables where owner='SOE';
exit;
EOF2
}

echo "Check schema objects on the auxiliary"
function check_aux_db {
export ORACLE_SID=dup_db
$ORACLE_HOME/bin/sqlplus -s '/ as sysdba' <<EOF2
set pagesize 999 linesize 999 heading off feedback off
select name, open_mode from v$database;
select table_name, num_rows from dba_tables where owner='SOE';
exit;
EOF2
}

drop_aux_db
backup_source_db
check_source_db_backup
nomount_aux_db
dup_aux_db
check_source_db
check_aux_db

Set execute permissions on the script dup_db.sh using the chmod command.
```
$ chmod +x dup_db.sh
```
On the duplicate host (that hosts the duplicate database), run the dup_db.sh script.

The following command runs the dup_db.sh script that is stored in the /home/my_scripts/duplication directory:

$ ./home/my_scripts/duplication/dup_db.sh