RMAN Duplicate from Active Database

Active database duplication does not require backup of the source database. It duplicates the live source database to the destination host by copying the database files over the network to the auxiliary (clone) instance. RMAN duplicate database can copy the required files as image copies or backup sets.

• Prerequisites

• RMAN duplicate database to same SID

• RMAN Duplicate to different SID

Prerequisites

Before you begin with this activity, make sure below items are addressed

• Source database is running in Archive log mode

• Check for space requirements on target server

• Servers are able to ping each other

RMAN Duplicate Database to Same SID

We are going to clone prod database which is running on prod.dbagenesis.com host. We have another server clone.dbagenesis.com where only oracle software is installed and no database created.

We will be using RMAN duplicate from active database to copy prod database on clone server.

Configure Listener on clone server to accept incoming connections

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = clone.dbagenesis.com)(PORT = 1521))
    )
  )

SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (ORACLE_HOME = /u01/app/oracle/product/12.2.0/db_home)
      (SID_NAME = prod)
    )
  )

Start the listener on clone server

lsnrctl start listener

Configure tns entries on the prod server

prod_clone =
 (DESCRIPTION = 
   (ADDRESS_LIST =
     (ADDRESS = (PROTOCOL = TCP)(HOST = clone.dbagenesis.com)(PORT = 1521))
   )
 (CONNECT_DATA =
   (SERVICE_NAME = prod)
 )
)

Make sure to test the tnsping is working from prod to clone server

tnsping prod_clone

On prod server, create pfile from spfile and copy to clone server

SQL> create pfile from spfile;

scp $ORACLE_HOME/dbs/initprod.ora oracle@clone.dbagenesis.com:$ORACLE_HOME/dbs

Also copy the password file from prod to clone server

scp $ORACLE_HOME/dbs/orapwprod oracle@clone.dbagenesis.com:$ORACLE_HOME/dbs

If no password file exists, create one via below command and then copy

orapwd file=$ORACLE_HOME/dbs/orapwprod force=y

On the clone server, open the pfile that you copied from prod server and create directory locations

cat $ORACLE_HOME/dbs/initprod.ora

In my case I had to create below two main locations

mkdir -p <control_file_locations>
mkdir -p <adump_locations>

Also create data files and redo log files locations from source on clone server

mkdir -p <soruce_db_files_loc>
mkdir -p <source_redo_files_loc>

Take clone server database to nomount stage

export ORACLE_SID=prod

sqlplus / as sysdba
SQL> startup nomount;
SQL> exit;

Connect to rman on prod server to both prod database and also the auxiliary (clone) database

rman target sys auxiliary sys@prod_clone

--> give same sys password for both target and auxiliary

Lets duplicate the database via RMAN duplicate from active database

RMAN> duplicate target database to 'prod' from active database nofilenamecheck;

Once cloning is done, you should see below

On the clone server, check if the cloned database is open and running fine

RMAN Duplicate to different SID

We are going to clone prod database which is running on prod.dbagenesis.com host. We have another server clone.dbagenesis.com where only oracle software is installed and no database created.

We will be using RMAN duplicate from active database to copy prod database on clone server with a different name (SID).

Configure Listener on clone server to accept incoming connections

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = clone.dbagenesis.com)(PORT = 1521))
    )
  )

SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (ORACLE_HOME = /u01/app/oracle/product/12.2.0/db_home)
      (SID_NAME = clone)
    )
  )

Start the listener on clone server

lsnrctl start listener

Configure tns entries on the prod server

clone =
 (DESCRIPTION = 
   (ADDRESS_LIST =
     (ADDRESS = (PROTOCOL = TCP)(HOST = clone.dbagenesis.com)(PORT = 1521))
   )
 (CONNECT_DATA =
   (SERVICE_NAME = clone)
 )
)

Make sure to test the tnsping is working from prod to clone server

tnsping clone

On prod server, create pfile from spfile and copy to clone server

SQL> create pfile from spfile;

scp $ORACLE_HOME/dbs/initprod.ora oracle@clone.dbagenesis.com:$ORACLE_HOME/dbs/initclone.ora

Also copy the password file from prod to clone server

scp $ORACLE_HOME/dbs/orapwprod oracle@clone.dbagenesis.com:$ORACLE_HOME/dbs/orapwclone

If no password file exists, create one via below command and then copy

orapwd file=$ORACLE_HOME/dbs/orapwclone force=y

On the clone server, open the pfile that you copied from prod server. Replace prod with clone SID

vi $ORACLE_HOME/dbs/initclone.ora

:%s/prod/clone      --> replace prod with clone

Add below two parameters to change data files and log files locations while cloning database

*.db_file_name_convert='/u01/app/oracle/oradata/prod','/u01/app/oracle/oradata/clone'

*.log_file_name_convert='/u01/app/oracle/oradata/prod','/oradb/app/oracle/oradata/clone'

Save & exit

Create respective directories from the clone pfile. In my case, I had to create below directories

mkdir -p <control_file_locations>
mkdir -p <adump_locations>
mkdir -p <FRA_location>
mkdir -p /u01/app/oracle/oradata/clone

Also create data files and redo log files locations from source on clone server

mkdir -p <soruce_db_files_loc>
mkdir -p <source_redo_files_loc>

Take clone server database to nomount stage

export ORACLE_SID=clone

sqlplus / as sysdba
SQL> startup nomount;
SQL> exit;

Connect to rman on prod server to both prod database and also the auxiliary (clone) database

rman target sys auxiliary sys@clone

--> give same sys password for both target and auxiliary

Let's refresh or duplicate the database via RMAN duplicate from active database

RMAN> duplicate target database to 'clone' from active database nofilenamecheck;

Further Read

• Oracle active database cloning error

• Configure RMAN Default Channels