Have you ever encounter the error ORA-19804? if yes then the below solution will help you.
Reason: Oracle cannot reclaim disk space of specified bytes from the DB_RECOVERY_FILE_DEST_SIZE limit.
Action: There are five possible solutions:
1) Take frequent backup of recovery area using RMAN.
2) Consider changing RMAN retention policy.
3) Consider changing RMAN archivelog deletion policy.
4) Add disk space and increase DB_RECOVERY_FILE_DEST_SIZE.
5) Delete files from recovery area using RMAN.
I found this error ORA-198 when i am taking backup.
when i check the DB_RECOVERY_FILE_DEST_SIZE using "show parameter DB_RECOVERY_FILE_DEST_SIZE" if found it is 10GB. but i have 500GB free space.
So i have increased the space using the below command.
SQL> alter system set DB_RECOVERY_FILE_DEST_SIZE=100G;
After changing parameter my backup completed successfully.