ORA-00245: Control File Backup Failed; Target is Likely on a Local File System

In alert log I got an issue ORA-00245: control file backup failed; target is likely on a local file system. Regarding this issue, I checked the snapshot control file location on rman prompt and observed that it was on local file system. In RAC environment, Snapshot control file backup location should be on a shared disk group so that it can be visible or accessible to all RAC nodes.
Check the configured snapshot controlfile default location.

RMAN> show snapshot controlfile name;

starting full resync of recovery catalog
full resync complete
RMAN configuration parameters for database with db_unique_name ORAHOW are:
CONFIGURE SNAPSHOT CONTROLFILE NAME TO ‘/u01/app/oracle/product/11.2.0.4/dbhome_1/dbs/snapcf_ORAHOW2.f’; # default

Here you can see that controlfile is on a local file system, so to fix this issue configure it to a shared location.

To Configure the snapshot controlfile to a shared disk

Connect to target database, and issue the following command on RMAN prompt.
rman target /

RMAN> CONFIGURE SNAPSHOT CONTROLFILE NAME TO ‘<shared_disk>/snapcf_<DBNAME>.f’;

Let us take an example,

RMAN> CONFIGURE SNAPSHOT CONTROLFILE NAME TO ‘+RC_DATA/ORAHOW/snapcf_orahow.f’;

new RMAN configuration parameters:
CONFIGURE SNAPSHOT CONTROLFILE NAME TO ‘+RC_DATA/ORAHOW/snapcf_orahow.f’;
new RMAN configuration parameters are successfully stored
starting full resync of recovery catalog
full resync complete

Due to the changes made to the controlfile backup mechanism any instances in the cluster may write to the backup controlfile when making changes to the current controlfile. Therefore, the backup file needs to be visible to all instances.