The snapshot control file is a copy of a database control file created in an operating system-specific location by RMAN. RMAN creates the snapshot control file so that it has a consistent version of a control file to use when either resynchronizing the recovery catalog or backing up the control file.
You can specify a cluster file system or a raw device destination for the location of your snapshot control file. This file is shared across all nodes in the cluster and must be accessible by all nodes in the cluster. Run the following RMAN command to determine the configured location of the snapshot control file:
SHOW SNAPSHOT CONTROLFILE NAME;
You can change the configured location of the snapshot control file. For example, on Linux and UNIX systems you can specify the snapshot control file location as
$ORACLE_HOME/dbs/scf/snap_prod.cf by entering the following at the RMAN prompt:
CONFIGURE SNAPSHOT CONTROLFILE NAME TO '$ORACLE_HOME/dbs/scf/snap_prod.cf';
This command sets the configuration for the location of the snapshot control file for every instance of your cluster database. Therefore, ensure that the
$ORACLE_HOME/dbs/scf directory is shared by all nodes that perform backups.
CONFIGURE command creates persistent settings across RMAN sessions. Therefore, you do not need to run this command again unless you want to change the location of the snapshot control file.
To delete a snapshot control file you must first change the snapshot control file location, then delete the file at the older location, as follows:
CONFIGURE SNAPSHOT CONTROLFILE NAME TO 'new_name'; DELETE COPY OF CONTROLFILE;
Oracle Database Backup and Recovery Reference for more information about configuring the snapshot control file