Database Reference
In-Depth Information
To prevent an ORA-00245 error, the snapshot control file must be placed on a shared location or on ASM
DISKGROUP, ensuring that each instance of RAC database has the read and write ability on the file.
The following procedure explains the process to configure the snapshot control file on an ASM DISK GROUP:
RMAN> CONFIGURE SNAPSHOT CONTROLFILE NAME TO '+DG_RONDB/snapcf_RONDB.f';
Upon configuration, the following message will be displayed at RMAN prompt:
using target database control file instead of recovery catalog
new RMAN configuration parameters:
CONFIGURE SNAPSHOT CONTROLFILE NAME TO '+DG_RONDB\snapcf_RONDB.f;
new RMAN configuration parameters are successfully stored
To display snapshot control file configuration details, connect to an RMAN prompt and execute one of the
following commands:
RMAN> show all;
RMAN> show snapshot controlfile name;
Multiple Channels Configuration for RAC
On a RAC database, it is feasible to have multiple channels allocated and scattered over multiple instances to scale up
the backup and recovery workload. This section explains how to configure parallelism to enable load balancing for
a preallocated (automatic) or runtime RMAN channel.
Parallelism for Load Balancing
Parallelism must be configured in RMAN prior to making use of multichannel configuration for balancing the backup
and restore workload over multiple instances. The following example configures the parallelism and enables the load
balancing option, also overwriting any pre-existing parallelism configuration settings:
RMAN> configure device type disk parallelism 2;
new RMAN configuration parameters:
CONFIGURE DEVICE TYPE DISK PARALLELISM 2 BACKUP TYPE TO BACKUPSET;
new RMAN configuration parameters are successfully stored
RMAN> show all; -- shows RMAN configuration settings
RMAN configuration parameters for database with db_unique_name RONDB are:
........
CONFIGURE DEVICE TYPE DISK PARALLELISM 2 BACKUP TYPE TO BACKUPSET; <<<<<
Persistent Multichannel Configuration
To scale an RMAN backup workload over multiple instances, you need to allocate multiple channels directing the
connection to an individual instance. The allocation of channels can be a preconfigured or just a one-time (dynamic)
allocation.
