oracle database switchover and getting ORA-01017: invalid username/password; logon denied

Getting and error while doing the switchover to standby 

ORA-01017: invalid username/password; logon denied

[oracle@racdr1 ~]$ dgmgrl system/********
DGMGRL for Linux: Version 11.2.0.0 - 64bit Production

Copyright (c) 2000, 2009, Oracle. All rights reserved.

Welcome to DGMGRL, type "help" for information.
Connected.
DGMGRL> show configuration

Configuration - racdg

  Protection Mode: MaxPerformance
  Databases:
    RAC      - Primary database
    RAC_STBY - Physical standby database

Fast-Start Failover: DISABLED

Configuration Status:
SUCCESS

DGMGRL> 
DGMGRL> 
DGMGRL> switchover to 'RAC_STBY'
Performing switchover NOW, please wait...
New primary database "RAC_STBY" is opening...
Operation requires startup of instance "RAC2" on database "RAC"
Starting instance "RAC2"...
ORA-01017: invalid username/password; logon denied

Warning: You are no longer connected to ORACLE.

Please complete the following steps to finish switchover:
        start up instance "RAC2" of database "RAC"

DGMGRL> 

it is little annoying but looking carefully we can figure out the issue and that is I am tying to switchover with user system and that is not present in password file across primary and dr.

SQL> select * from v$pwfile_users;

USERNAME                       SYSDB SYSOP SYSAS
------------------------------ ----- ----- -----
SYS                            TRUE  TRUE  FALSE


SQL>

So the solution is try it with sys user as it is present in password file

[oracle@rac1 dbs]$ dgmgrl sys/********@RAC
DGMGRL for Linux: Version 11.2.0.0 - 64bit Production

Copyright (c) 2000, 2009, Oracle. All rights reserved.

Welcome to DGMGRL, type "help" for information.
Connected.
DGMGRL> 
DGMGRL> show configuration

Configuration - racdg

  Protection Mode: MaxPerformance
  Databases:
    RAC_STBY - Primary database
    RAC      - Physical standby database

Fast-Start Failover: DISABLED

Configuration Status:
SUCCESS

DGMGRL> 
DGMGRL> 
DGMGRL> switchover to 'RAC'
Performing switchover NOW, please wait...
Operation requires a connection to instance "RAC2" on database "RAC"
Connecting to instance "RAC2"...
Connected.
New primary database "RAC" is opening...
Operation requires startup of instance "RAC_STBY1" on database "RAC_STBY"
Starting instance "RAC_STBY1"...
ORACLE instance started.
Database mounted.
Database opened.
Switchover succeeded, new primary is "RAC"
DGMGRL> 
DGMGRL> 
DGMGRL> show configuration

Configuration - racdg

  Protection Mode: MaxPerformance
  Databases:
    RAC      - Primary database
    RAC_STBY - Physical standby database

Fast-Start Failover: DISABLED

Configuration Status:
SUCCESS


DGMGRL>