This parameter defines the maximum size in kilobytes of the backup pieces created by RMAN with an external backup library, that is,
backup_dev_type = rman_util).Syntax:
rman_kybtes = <number>Default:
0 (no limit)You can also use this parameter to limit the size of a save set created by an RMAN incremental backup to disk.
See also:
RMAN Backup with an External Backup LibraryOracle documentation