Upgrading to Oracle 12c - Expert Consolidation in Oracle Database 12c - page 448

RMAN> alter system set db_recovery_file_dest_size = 20G;
Statement processed
RMAN> alter system set db_recovery_file_dest = '+RECO';
Statement processed
RMAN> ALTER SYSTEM SET CONTROL_FILES='+DATA','+RECO' scope=spfile;
Statement processed
Now restart the instance once more in preparation of the restore of the control file, ensure you perform a “startup
nomount.” The restore command does not require a backup of the control file, you can simply pick one of the original
ones. If unsure, refer to the file list generated before the migration. In the example, the copy in /u01/oradata
was restored:
RMAN> restore controlfile from autobackup;
Starting restore at 15.08.2013 18:14
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=13 device type=DISK
recovery area destination: /u01/fra
database name (or database unique name) used for search: CDB2
channel ORA_DISK_1: AUTOBACKUP /u01/fra/CDB2/autobackup/2013_08_15/o1_mf_s_823542889_90t1yso5_.bkp
found 
in the recovery area
channel ORA_DISK_1: looking for AUTOBACKUP on day: 20130815
channel ORA_DISK_1: restoring control file from AUTOBACKUP /u01/fra/CDB2/autobackup/2013_08_15/
o1_mf_s_823542889_90t1yso5_.bkp
channel ORA_DISK_1: control file restore from AUTOBACKUP complete
output file name=+DATA/CDB2/CONTROLFILE/current.278.823544041
Finished restore at 15.08.2013 18:14
Mount the database in preparation for the switchover operation. In the next step you perform the switchover and
recovery:
RMAN> alter database mount;
[...]
RMAN> switch database to copy;
Starting implicit crosscheck backup at 15.08.2013 18:15
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=13 device type=DISK
Finished implicit crosscheck backup at 15.08.2013 18:15