oracle@oracle:/oracle/TWOTST/orahome # env| grep ORA
ORACLE_SID=TWOTST
ORA_NLS10=/oracle/TWOTST/orahome/nls/data
ORACLE_BASE=/oracle/TWOTST
ORACLE_SW=/oracle/product/19.16.0.0.0p1
ORACLE_HOME=/oracle/TWOTST/orahome

oracle@oracle:/oracle/DUPTST/orahome # env| grep ORA
ORACLE_SID=DUPTST
ORA_NLS10=/oracle/DUPTST/orahome/nls/data
ORACLE_BASE=/oracle/DUPTST
ORACLE_SW=/oracle/product/19.16.0.0.0p1
ORACLE_HOME=/oracle/DUPTST/orahome

instance_name=DUPTST
db_name=DUPTST
control_files="/oracle/data1/DUPTST/controlfile/control01.ctl"
control_files="/oracle/data2/DUPTST/controlfile/control02.ctl"

• CONNECT to the source database as TARGET
• CONNECT to the auxiliary instance
• CONNECT to CATALOG

 RMAN> CONNECT TARGET SYS@TWOTST;    # source database
 connected to target database: PROD (DBID=1234567)

 RMAN> CONNECT AUXILIARY SYS@DUPTST; # duplicate database instance
 connected to auxiliary database: DUPDB (not mounted)

 RMAN> CONNECT CATALOG rman_owner@ONETST;    # recovery catalog database
 connected to recovery catalog database

 run {
  ALLOCATE AUXILIARY CHANNEL c1 DEVICE TYPE disk;
  ALLOCATE AUXILIARY CHANNEL c2 DEVICE TYPE disk;
SET NEWNAME FOR DATAFILE 1 /oracle/data4/TWOTST/datafile/system_001.dbf
SET NEWNAME FOR DATAFILE 2 /oracle/data4/TWOTST/datafile/sysaux_001.dbf
SET NEWNAME FOR DATAFILE 3 /oracle/data4/TWOTST/datafile/databyhora.dbf
SET NEWNAME FOR DATAFILE 4 /oracle/data4/TWOTST/datafile/tools_001.dbf
SET NEWNAME FOR DATAFILE 5 /oracle/data4/TWOTST/datafile/data_001.dbf
SET NEWNAME FOR DATAFILE 6 /oracle/data4/TWOTST/datafile/undotwo_001.dbf
SET NEWNAME FOR DATAFILE 7 /oracle/data4/TWOTST/datafile/data_002.dbf
  DUPLICATE TARGET DATABASE TO 'DUPDB'
  SKIP TABLESPACE tools
  LOGFILE
    GROUP 1 ('/oracle/data1/TWOTST/onlinelog/redo1_1.rdo',
		   '/oracle/data1/TWOTST/onlinelog/redo2_1.rdo',
		   '/oracle/data1/TWOTST/onlinelog/redo3_1.rdo',	  
             '/oracle/data1/TWOTST/onlinelog/redo4_1.rdo') SIZE 200M REUSE, 
    GROUP 2 ('/oracle/data1/TWOTST/onlinelog/redo2_1.rdo', 
		   '/oracle/data1/TWOTST/onlinelog/redo2_2.rdo',
		   '/oracle/data1/TWOTST/onlinelog/redo3_2.rdo',	  
             '/oracle/data1/TWOTST/onlinelog/redo4_2.rdo') SIZE 200M REUSE, 
  }