ASM disk group state shows as ‘CONNECTED’

As we know, normally disk group state is ‘MOUNTED’ or ‘DISMOUNTED’, etc. Today, when I ran the following query, two disk group state shows as ‘CONNECTED’:

SQL> select NAME,STATE from v$asm_diskgroup ;

NAME       STATE 
---------- ---------
DATA       CONNECTED                                                      
RECO       CONNECTED 
...
..
.

According to Oracle doc, ‘CONNECTED’ means disk group is in use by the database instance:

STATEVARCHAR2(11)State of the disk group relative to the instance:
CONNECTED – Disk group is in use by the database instance
BROKEN – Database instance lost connectivity to the Oracle ASM instance that mounted the disk group
UNKNOWN – Oracle ASM instance has never attempted to mount the disk group
DISMOUNTED – Disk group was cleanly dismounted by the Oracle ASM instance following a successful mount
MOUNTED – Instance is successfully serving the disk group to its database clients
QUIESCING – CRSCTL utility attempted to dismount a disk group that contains the Oracle Cluster Registry (OCR). The disk group cannot be dismounted until Cluster Ready Services (CRS) exits, because the disk group contains the OCR.

RMAN-06136: ORACLE error from auxiliary database: ORA-00201: control file version 11.2.0.4.0 incompatible with ORACLE version 11.2.0.0.0

  1. Check parameter ‘compatible’ on both source and target databases.
  2. Set compatible value the same on target as on the source.
  3. Rerun RMAN duplicate database again.