Prerequisites

• identical oracle version on target and clone
• identical filesystem on target and clone
• identical database name
• target and clone on different computer

Before the duplication

Create an oracle password file on the clone

# orapwd file=$ORACLE_HOME/dbs/orapwINSTC password=<password>

Add the following to tnsnames.ora on the clone

INSTP =
    (DESCRIPTION =
        (ADDRESS_LIST =
            (ADDRESS = (PROTOCOL = TCP)(HOST = instp)(PORT = 1521))
        )
        (CONNECT_DATA =
            (ORACLE_SID = INSTP)
        )
    )

Start the database on the target

# sqlplus / as sysdba
SQL> startup

Duplication in RMAN

Start RMAN on the target and connect to the target and clone

# rman target sys/<password>@INSTP clone sys/<password>@INSTC

Start the clone with nomount

rman> startup clone nomount

Issue the duplicate command ("to INSTP" defines the database name)

rman> duplicate target database to INSTP from active database nofilenamecheck;