Oracle 11g rac rman ORA-00245 control file backup operation failed error and control file backup description

 

 

I. Problem Description

OS: RedHat 5.8

Database: 11.2.0.3

2 node RAC.

 

When using RMAN for backup, the following error is reported:

ORA-00245: control file backup failed; target is likely on a local file system

 

This issue only exists in RAC environments after Oracle 11gr2.

 

2. ORA-245 trigger conditions

ORA-00245 errors may occur in five of the following environments.

 

2.1 RAC environment, automatic backup of control files will fail due to ORA-245 errors

 

Autobackup of controlfile in RMAN isfailing with error:
RMAN-571: ========================================================== ==============================
RMAN-569: ==================== error message stack follows ==========================
RMAN-571: ========================================================== ==============================
RMAN-3009: failure of control file and spfile autobackup command on
Ora_disk_1 channel at 10/27/2010 12:13:31
ORA-245: control file backup operation failed

 

2.2 In the RAC environment, backup control files to non-shared local paths will also fail

SQL> alter Database Backup controlfileto '/u01/backup/control. BK' Reuse
*
Error at line 1:
ORA-245: control file backup operation failed

 

2.3 In the RAC environment, creating a standby controlfile to a non-shared local path will also fail

SQL> alter database create standby controlfileas '/home/Oracle/renostdbycntrl. CTL ';

Alter database create standby controlfileas
'/Home/Oracle/renostdbycntrl. CTL'
*
Error at line 1:
ORA-245: control file backup operation failed

 

2.4 copy the current control file to the local path in the RAC Environment

Channel metadata: Starting datafile copy
Copying Current Control File
RMAN-571: ========================================================== ==============================
RMAN-569: ==================== error message stack follows ==========================
RMAN-571: ========================================================== ==============================
RMAN-3009: failure of Backup command on 10/07/2011 11:36:42 channel at least
ORA-245: control file backup operation failed

 

 

2.5 In the RAC environment, if the controlfile snapshot is backed up to a non-shared location, the RMAN backup will also fail.

RMAN-00571: ========================================================== ======================
RMAN-00569: ============== error message stack follows ==================
RMAN-00571: ========================================================== ========================
RMAN-03009: failure of Resync command on default channel at 03/13/2012 10:19:41
ORA-00245: control file backup operation failed

 

 

Iii. Cause of error

 

From 11gr2onwards, The controlfile backup happens without holding the controlfileenqueue. for non-RAC database, this doesn' t change anything. but for racdatabase, 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 thissnapshot controlfile need to be visible to all instances.

-- From oracle11gr2, controlfile enqueue does not need to be locked when backing up the control file. For non-RAC databases, there is no change, but for RAC databases, any instance in the cluster can be written to the snapshot control file due to changes in the control file backup mechanism, therefore, snapshot controlfile must be visible to all instances.

 

In racenvironment any form of controlfile backup may fail with ORA-0245 if thelocation of the snapshot controlfile is not a shared location.

-- In a RAC environment, if the snapshot controlfile is not in the shared location, any form of control file can report an error in the ORA-245.

 

The backup ofthe controlfile actualy makes a backup of the snapshot controlfile. thesnapshot controlfile is created when the controlfile is about to be backed up.

-- The backup of the control file actually generates a snapshot controlfile, which generates a snapshot file during Backup.

 

The snapshotcontrolfile is a read-consistent copy of The controlfile.

-- The snapshot control file is a read-consistent copy of the control file.

 

The snapshotcontrolfile must be accessible by all nodes of a RAC database, if the snapshotcontrolfile does not reside on a shared device error will be raised at the timeof RMAN backup while taking snapshot of controlfile.

-- The snapshot control file must be accessible to all nodes. If the snapshot control file is not stored on a shared device, an error is reported when RMAN backs up the snapshot of the control file.

 

This applies to backingup controlfile using sqlplus/having autobackup of controlfileconfigured on non-shared location.

 

 

Error Message description ORA-245
----------------------------------------
00245,000 00, "control file backup operation failed"
* Cause: failed to create a control file backup because some process signaled anerror during Backup creation.
* Action: Check alert files for further information. this usually happens becausesome process cocould not access the backup file during Backup creation. anyprocess of any instance that starts a read/write control file transaction musthave an access to the backup control file during Backup creation.

 

 

Iv. Solution

 

4.1. Check the snapshot Control File Location

RMAN> show snapshot controlfile name;

 

4.2 configure snapshot controlfile to a shared location

RMAN> Configure snapshot controlfilename to '<shared_disk>/snapcf _ <dbname>. F ';

 

If ASM is used, specify the corresponding ASM disk group:

RMAN> Configure snapshot controlfilename to '+ <diskgroup>/snapcf _ <dbname>. F ';

 

 

Reference:

In RAC environment from 11.2 onwards backupor snapshot controlfile needs to be in shared location [ID 1472171.1]

RMAN backup fails with Ora-00245 AndRman-08132 [ID 1365484.1]

RMAN backup to local device with snapshoton shared fails ORA-00245 [ID 1516654.1]

 

 

 

 

 

Bytes ---------------------------------------------------------------------------------------

All rights reserved. reprinted articles are allowed, but source addresses must be indicated by links. Otherwise, the documents will be held legally responsible!

Skype: tianlesoftware

QQ: tianlesoftware@gmail.com

Email: tianlesoftware@gmail.com

Blog: http://blog.csdn.net/tianlesoftware

WEAVER: http://weibo.com/tianlesoftware

Twitter: http://twitter.com/tianlesoftware

Facebook: http://www.facebook.com/tianlesoftware

LinkedIn: http://cn.linkedin.com/in/tianlesoftware