Snapshot controlfile feature with RMAN

Last updated on September 3rd, 2016 at 01:38 am

When RMAN needs to re-synchronize from a read-consistent version of the control file, it creates a temporary snapshot control file. RMAN needs a snapshot control file only when resynchronizing with the recovery catalog or when making a backup of the current control file.

The default value for the snapshot control file is platform-specific and depends on the Oracle home. For example, the default filename on some UNIX platforms in Oracle Database 10g is $ORACLE_HOME/dbs/snapcf_@.f. Note that if you have a flash recovery area configured, the default location for the snapshot control file is not the flash recovery area.

As of Oracle 11.2 ( to more precise) the snapshot control file must be on a location shared by all RAC nodes in a cluster (it must be accessible by all nodes on which instances for an RAC database can run). If you do not do so, you most likely will receive an ORA-00245 (ORA-00245: control file backup operation failed) when running an RMAN backup.
CONFIGURE SNAPSHOT CONTROLFILE NAME TO ‘/oracle/dbs/snapcf_test.f’; # default
CONFIGURE SNAPSHOT CONTROLFILE NAME TO ‘<shared snapshot control file>’;

You can Restore using snapshot controlfile also

restore controlfile from ‘/u01/app/oracle/product/11.2.0/db_1/dbs/snapcf_test.f’;

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