Using the RMAN CLI command delete backupset hangs right after you select Yes to the following prompt:
Do you really want to delete the above objects (enter YES or NO)? yes
RMAN does hang because there is no response from NetVault when the delete command of RMAN is executed.
Unfortunately, currently the Oracle APM media manager layer does not support the RMAN delete backupset command against the netVault backup job.
There is an enhancement request for the Oracle APM media manager layer to support the RMAN delete backupset command.
-- Do not use the RMAN delete backupset command against the netVault backup job until it is supported