ORA-00245: control file backup failed; in Oracle RAC, target might not be on shared storage

RAC database backup with RMAN failed with error:

Starting Control File and SPFILE Autobackup at 2015-09-14:23:13:44
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03009: failure of Control File and SPFILE Autobackup command on Disk channel at 2015-09-14:23:13:45
ORA-00245: control file backup failed; in Oracle RAC, target might not be on shared storage

This is because From 11gR2 onwards, the controlfile backup happens without holding the controlfile enqueue. For non-RAC database, this doesn't change anything. But for RAC database, due to the changes made to the controlfile backup mechanism in 11gR2, any instance in the cluster may write to the snapshot controlfile. Due to this snapshot controlfile need to be visible to all instances. The snapshot controlfile MUST be accessible by all nodes of a RAC database, if the snapshot controlfile does not reside on a shared device error will be raised at the time of RMAN backup while taking snapshot of controlfile. This applies to backing up controlfile using sqlplus / having autobackup of controlfile configured on non shared location.
Solution:
This is a RAC specific configuration issue and the correct configuration is as described below It is changed behaviour which requires that the snapshot controlfile in a RAC environment, is on a shared location.
Check the snapshot controlfile location:

RMAN> show snapshot controlfile name;

Configure the snapshot controlfile to a shared disk :

RMAN> CONFIGURE SNAPSHOT CONTROLFILE NAME TO '+DG01/snapcf_RACDB.f';

RMAN warnings RMAN-06207, RMAN-06208 due to mismatched status for snapshot controlfile

Hello, Today I faced next warnings in database backup log :

RMAN-06207: WARNING: 1 objects could not be deleted for DISK channel(s) due
RMAN-06208:          to mismatched status.  Use CROSSCHECK command to fix status
RMAN-06210: List of Mismatched objects
RMAN-06211: ==========================
RMAN-06212:   Object Type   Filename/Handle
RMAN-06213: --------------- ---------------------------------------------------
RMAN-06214: Datafile Copy   /u01/app/oracle/product/11.2.0/dbhome_1/dbs/snapc_testdb.f

To solve this warnings we need to change snapshot controlfile name to another file and after that delete mismatched file.

rman target /

Recovery Manager: Release 11.2.0.3.0 - Production on Wed Jul 19 18:14:56 2017

Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.

connected to target database: TESTDB (DBID=2665187923)

RMAN> show all;

using target database control file instead of recovery catalog
RMAN configuration parameters for database with db_unique_name TESTDB are:
CONFIGURE RETENTION POLICY TO REDUNDANCY 1; # default
CONFIGURE BACKUP OPTIMIZATION OFF; # default
CONFIGURE DEFAULT DEVICE TYPE TO DISK;
CONFIGURE CONTROLFILE AUTOBACKUP ON;
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE 'DISK' TO '%F';
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '%F'; # default
CONFIGURE DEVICE TYPE DISK PARALLELISM 1 BACKUP TYPE TO BACKUPSET; # default
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE MAXSETSIZE TO UNLIMITED; # default
CONFIGURE ENCRYPTION FOR DATABASE OFF; # default
CONFIGURE ENCRYPTION ALGORITHM 'AES128'; # default
CONFIGURE COMPRESSION ALGORITHM 'BASIC' AS OF RELEASE 'DEFAULT' OPTIMIZE FOR LOAD TRUE ; # default
CONFIGURE ARCHIVELOG DELETION POLICY TO NONE; # default
CONFIGURE SNAPSHOT CONTROLFILE NAME TO '/u01/app/oracle/product/11.2.0/dbhome_1/dbs/snapc_testdb.f';

RMAN> CONFIGURE SNAPSHOT CONTROLFILE NAME TO '/u01/app/oracle/product/11.2.0/dbhome_1/dbs/snapc_testdb1.f';
RMAN> crosscheck copy;
RMAN> delete expired copy;

Reconfigure virtual machine Device is a SCSI controller engaged inbus-sharing

When we were installing RAC on vmware appear error:

virtual machine Device is a SCSI controller engaged inbus-sharing

while adding already created hard disk with reuse option in vmware.

This happend because we created snapshot.
Solution is remove snapshot, add disk and after that if you want to have a snapshot take new one.