sqlplus / as sysdba
…
alter system set db_recovery_file_dest_size=25G scope=both;
alter system set db_recovery_file_dest=’/oracle/fra’ scope=both; # yes this path better exist with space allocated to at least “size” above
alter system set log_archive_dest_1=’location=USE_DB_RECOVERY_FILE_DEST’ scope=both;
alter system set log_archive_dest_state_1=enable scope=both;
A sub-directory under “fra” will be created with the SID of the DB. And under that sub-dirs for whatever oracle is doing there: archivelog, onlinelog, flashback, backupset, autobackup etc.
If you are not in archivelog mode you will need to enable it:
shutdown immediate;
startup mount;
alter database archivelog;
alter database open;
See Oracle’s documentation for further info:
12c Oracle FRA Documentation