Oracle Error Message
RMAN-20223: DB_UNIQUE_NAME mismatch in snapshot control file
Reason for the Error
The DB_UNIQUE_NAME value in the snapshot control file was incorrect. This error can occur in Oracle RAC when the snapshot control file location is not shared across nodes and virtual IPs are setup in the remote database from where resynchronization is done using RESYNC CATALOG FROM DB_UNIQUE_NAME commnad.
To avoid this error, one of the following actions can be taken: 1) Share the control file snapshot location. The snapshot location can be displayed by executing SHOW SNAPSHOT CONTROLFILE NAME at the RMAN prompt. 2) Do not use Virtual IPs in the service name used to define the connect identifiers. The connect identifiers can be displayed using SHOW DB_UNIQUE_NAME command at the RMAN prompt.