Using the following rman command one can setup to keep 2 days of archive log on disk and also archive them to tape/disk the ones that haven’t been sent to.

connect target /
connect rmancatalog/rmancatalog@catalog

run {
# tells to backup all archive logs that haven’t been backed up one time which prevents from backing up more than once to
backup archivelog all not backed up 1 times;
# deletes archive log more than 2 days old, as the 2nd command runs after the first one so if some reason first one fails the delete step won’t run
delete archivelog until time ‘SYSDATE-2’;
}

There is another way of doing which is:
# set the following parameter in the rman parameters
CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE SBT_TAPE TO 1;
run {
delete archivelog all completed before ‘sysdate-2’;
}

• Backup & Recovery
• RMAN