Problem Description
Oracle Direct-to-Cloud (DTC) incremental backup jobs fail with the application error Oracle_DTC5. The backup job terminates during RMAN execution with an Oracle error indicating that the control file backup could not be completed.
The job logs report the following failure messages:
ORA-00245: control file backup failedOracle RAC target might not be on shared storageNo Configured RAC Instance Available for Execution
Cause
The backup failures are caused by the control file not being located on shared storage in an Oracle Real Application Clusters (RAC) environment, compounded by wallet-based authentication being enabled.
In an Oracle RAC environment:
Control files must reside on shared storage (ASM or a shared filesystem) accessible by all cluster nodes.
RMAN allocates and opens channels across multiple RAC nodes during backup operations.
Because the control file was stored on the local storage of a single node, RMAN channels executing on other RAC nodes could not access it. Furthermore, when wallet authentication is utilized, RMAN fails to correctly associate and authenticate channels across nodes if configurations mismatch, resulting in the backup failing with ORA-00245 and Oracle_DTC5.
Traceback / Logs
RMAN Error Stack:
ORA-00245: control file backup failed Oracle RAC, target might not be on shared storage
Application-Level Error:
Oracle_DTC5 No Configured RAC Instance Available for Execution [No RAC Instance is available for execution]
Verification: Control File Location
To verify whether the control files are properly located on shared storage, run the following query from SQL*Plus on any active RAC node:
SELECT name FROM v$controlfile;
Expected (Correct – Shared Storage Example):
+DATA/DBNAME/CONTROLFILE/current.256.113456789 +FRA/DBNAME/CONTROLFILE/current.257.113456790
Incorrect (Local Storage – Causes Failure Example):
/u01/app/oracle/oradata/DBNAME/control01.ctl
Resolution
Follow these steps to resolve the issue:
Step 1: Relocate Control Files to Shared Storage
Ensure all Oracle control files are configured on shared storage (ASM or a clustered filesystem) that is simultaneously accessible by all RAC nodes.
Note: Relocating control files requires database downtime.
If the control files are currently on local storage, migrate them to ASM or shared storage using standard Oracle RMAN restoration methods.
Update the
control_filesparameter in the database SPFILE/PFILE to point to the new shared storage paths.Restart the Oracle RAC database cluster to apply changes.
Step 2: Harmonize Wallet Configuration Across RAC Nodes
If wallet-based authentication is enabled, ensure absolute consistency across the cluster:
Verify that the wallet directory exists and is accessible on every RAC node.
Confirm that the wallet path, contents, and file permissions (
chmod 600/ ownership) are identical across all nodes.Ensure no individual node is missing the required wallet credentials.
Step 3: Retry the Backup
Once the control files are verified on shared storage and the wallet configuration is consistent across all nodes, re-run the Druva Phoenix RMAN backup job.