I have a file system for my archives which gets full in a short span of time. I want RMAN to backup all the archives automatically and delete the archives after backing it up when the archives mount-point gets full.
Is that possible?
Yes, it is.
BACKUP ARCHIVELOG ALL DELETE ALL INPUT;
See: Deleting Archived Redo Logs After Backups in non-CDBs
Or you can use FRA and configure an archivelog deletion policy:
CONFIGURE ARCHIVELOG DELETION POLICY TO BACKED UP 1 TIMES TO DEVICE TYPE DISK';
This way when the FRA is getting full, the database will automatically delete already backed up archivelogs.
See: CONFIGURE delalConf