You configured the default backup device type as disk for RMAN backups. In your database, because of
business requirements, you have to take a simultaneous duplicate backup of the data files when the RMAN
BACKUP command is used.
What must you set using the RMAN CONFIGURE command to achieve this?
MAXSETSIZE TO 2;
DEVICE TYPE DISK PARALLELISM 2;
RETENTION POLICY TO REDUNDANCY 2;
DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 2;
Duplexing Backup Sets with CONFIGURE BACKUP COPIES (Link)