Tales From A Lazy Fat DBA

If you want the duplicate filenames to be the same as the target filenames, and if the databases are in different hosts, then you must specify NOFILENAMECHECK.

If duplicating a database on the same host as the target database, do not specify the NOFILENAMECHECKoption. Otherwise, RMAN may signal this error:

RMAN-10035: exception raised in RPC: ORA-19504: failed to create file 
            "/oracle/dbs/tbs_01.f" 
ORA-27086: skgfglk: unable to lock file - already in use 
SVR4 Error: 11: Resource temporarily unavailable 
Additional information: 8 
RMAN-10031: ORA-19624 occurred during call to 
DBMS_BACKUP_RESTORE.RESTOREBACKUPPIECE