Configuring ASM Targets for Monitoring

According to 

G Configuring Database and ASM Targets for Monitoring

1. Set the monitoring credentials for Oracle ASM. To do so, follow these steps:
   
   1. In Grid Control, click Targets and then Databases.
      
   2. On the Databases page, find and select the Oracle ASM target and click Monitoring Configuration.
      
   3. On the Properties page, specify the password for the ASMSYS user in the Password field. To verify the monitoring credentials, click Test Connection.
      
   4. If the connection is successful, click Next, then click Submit.
      

I  found the solution for EM 12c Cloud Control to monitor RAC ASM instances.

[grid@orarac2poc admin]$ cat tnsnames.ora
+ASM2 =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = orarac2poc)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = +ASM)
      (INSTANCE_NAME=+ASM2)(UR=A)
    )
  )




[grid@orarac2poc admin]$ lsnrctl service LISTENER

LSNRCTL for Linux: Version 11.2.0.2.0 - Production on 17-JAN-2013 15:00:55

Copyright (c) 1991, 2010, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=LISTENER)))
Services Summary...
Service "+ASM" has 1 instance(s).
  Instance "+ASM2", status READY, has 1 handler(s) for this service...
    Handler(s):
      "DEDICATED" established:0 refused:0 state:ready
         LOCAL SERVER
Service "DGS.POC" has 1 instance(s).
  Instance "DGS", status READY, has 1 handler(s) for this service...
    Handler(s):
      "DEDICATED" established:19 refused:0 state:ready
         LOCAL SERVER
Service "DGS_DGB.POC" has 1 instance(s).
  Instance "DGS", status READY, has 1 handler(s) for this service...
    Handler(s):
      "DEDICATED" established:19 refused:0 state:ready
         LOCAL SERVER
Service "DGS_DGMGRL.POC" has 1 instance(s).
  Instance "DGS", status UNKNOWN, has 1 handler(s) for this service...
    Handler(s):
      "DEDICATED" established:0 refused:0
         LOCAL SERVER
Service "DGXDB.POC" has 1 instance(s).
  Instance "DGS", status READY, has 1 handler(s) for this service...
    Handler(s):
      "D000" established:0 refused:0 current:0 max:1022 state:ready
         DISPATCHER
         (ADDRESS=(PROTOCOL=tcp)(HOST=orarac2poc)(PORT=16735))
Service "ORCL" has 1 instance(s).
  Instance "ORCL2", status READY, has 1 handler(s) for this service...
    Handler(s):
      "DEDICATED" established:90 refused:0 state:ready
         LOCAL SERVER
Service "ORCLXDB" has 1 instance(s).
  Instance "ORCL2", status READY, has 1 handler(s) for this service...
    Handler(s):
      "D000" established:0 refused:0 current:0 max:1022 state:ready
         DISPATCHER
         (ADDRESS=(PROTOCOL=tcp)(HOST=orarac2poc)(PORT=65288))
Service "RCAT" has 1 instance(s).
  Instance "RCAT", status READY, has 1 handler(s) for this service...
    Handler(s):
      "DEDICATED" established:1327 refused:0 state:ready
         LOCAL SERVER
Service "RCATXDB" has 1 instance(s).
  Instance "RCAT", status READY, has 1 handler(s) for this service...
    Handler(s):
      "D000" established:0 refused:0 current:0 max:1022 state:ready
         DISPATCHER
         (ADDRESS=(PROTOCOL=tcp)(HOST=orarac2poc)(PORT=16926))
The command completed successfully


[grid@orarac2poc ~]$ sqlplus / as sysasm

SQL*Plus: Release 11.2.0.2.0 Production on Thu Jan 17 14:54:18 2013

Copyright (c) 1982, 2010, Oracle.  All rights reserved.


Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - 64bit Production
With the Real Application Clusters and Automatic Storage Management options

SQL> select * from v$pwfile_users;

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

SQL> alter user asmsnmp identified by oracle123;

User altered.

SQL> exit
Disconnected from Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - 64bit Production
With the Real Application Clusters and Automatic Storage Management options




Disconnected from Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - 64bit Production
With the Real Application Clusters and Automatic Storage Management options
[grid@orarac2poc admin]$ sqlplus asmsnmp/oracle123@+ASM2  as sysasm

SQL*Plus: Release 11.2.0.2.0 Production on Thu Jan 17 15:04:08 2013

Copyright (c) 1982, 2010, Oracle.  All rights reserved.

ERROR:
ORA-01031: insufficient privileges


Enter user-name:
[grid@orarac2poc admin]$ sqlplus asmsnmp/oracle123@+ASM2  as sysdba

SQL*Plus: Release 11.2.0.2.0 Production on Thu Jan 17 15:04:12 2013

Copyright (c) 1982, 2010, Oracle.  All rights reserved.


Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - 64bit Production
With the Real Application Clusters and Automatic Storage Management options

SQL> exit
Disconnected from Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - 64bit Production
With the Real Application Clusters and Automatic Storage Management options