在数据库版本 188.8.131.52 dataguard上备份有以下的错误：
Starting backup at 2016-03-15 14:12:35 RMAN-06820: WARNING: failed to archive current log at primary database ORACLE error from target database: ORA-17629: Cannot connect to the remote database server ORA-17627: ORA-00942: table or view does not exist
Do not use operating system authentication to login with RMAN. Use a username and password.
That is, do not use just the "/" (operating system authentication) connect to the standby database:
Instead put in the username and password for the SYSDBA user: