在RAC的一个节点上使用rman通过tns（SCAN）连接时报错：
[oracle@rac1 ~]$ rman target system/system@orarac
Recovery Manager: Release 12.1.0.1.0 - Production on Mon Mar 23 13:35:40 2015
Copyright (c) 1982, 2013, Oracle and/or its affiliates. All rights reserved.
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-00554: initialization of internal recovery manager package failed
RMAN-04005: error from target database:
ORA-01017: invalid username/password; logon denied
而下面的连接没有问题：
[oracle@rac1 ~]$ rman target system/system
Recovery Manager: Release 12.1.0.1.0 - Production on Mon Mar 23 13:39:07 2015
Copyright (c) 1982, 2013, Oracle and/or its affiliates. All rights reserved.
connected to target database: ORARAC (DBID=377624869)
RMAN>
使用sys用户通过tns则可以连接：
[oracle@rac1 ~]$ rman target sys/system@orarac
Recovery Manager: Release 12.1.0.1.0 - Production on Mon Mar 23 13:41:11 2015
Copyright (c) 1982, 2013, Oracle and/or its affiliates. All rights reserved.
connected to target database: ORARAC (DBID=377624869)
RMAN>
我们给system用户授予sysdba权限测试一下：
[oracle@rac1 ~]$ sqlplus "/as sysdba"
SQL*Plus: Release 12.1.0.1.0 Production on Mon Mar 23 13:42:27 2015
Copyright (c) 1982, 2013, Oracle. All rights reserved.
Connected to:
Oracle Database 12c Enterprise Edition Release 12.1.0.1.0 - 64bit Production
With the Partitioning, Real Application Clusters, Automatic Storage Management, OLAP,
Advanced Analytics and Real Application Testing options
SQL> grant sysdba to system;
Grant succeeded.
再次在rman中使用system用户通过tns连接target：
[oracle@rac1 ~]$ rman target system/system@orarac
Recovery Manager: Release 12.1.0.1.0 - Production on Mon Mar 23 13:43:22 2015
Copyright (c) 1982, 2013, Oracle and/or its affiliates. All rights reserved.
connected to target database: ORARAC (DBID=377624869)
RMAN>
OK了（其实上面的测试也适用于远程使用rman连接target数据库），在这次测试中可以有下面的结论：
1、rman中（在远程机器或服务器上）使用tnsname连接target数据库时，需要用户具有SYSDBA权限；
2、rman中（在服务器上）不通过tnsname连接target数据库时，可以不需要SYSDBA权限；