ERROR:

CREATE CONFIGURATION my_dg_config AS PRIMARY DATABASE IS bvtb CONNECT IDENTIFIER IS bvtb;
Error: ORA-16501: The Oracle Data Guard broker operation failed.
Error: ORA-16625: cannot reach database "dktb"

SOLUTION:

Check log tại đường dẫn

cat /u01/app/oracle/diag/rdbms/bvtb/bvtb/trace/drcbvtb.log

Nếu báo lỗi

Failed to mount standby database.
Database Resource SetState Error (16746)
SQL Execution error=604, sql=[ALTER DATABASE RECOVER MANAGED STANDBY DATABASE DISCONNECT  NODELAY]. See error stack belo

Thì chạy câu lệnh sau

alter database recover managed standby database using current logfile disconnect from session;