All data files (including an undo tablespace for each instance) and redo log files (at least two for each instance) for an Oracle RAC database must reside on shared storage. Oracle recommends that you use Oracle ASM to store these files in an Oracle ASM disk group.
Oracle supports alternative ways of using shared storage, such as certified cluster file systems. In addition, Oracle recommends that you use one shared server parameter file (SPFILE) with instance-specific entries. Oracle RAC 12c allows storing shared password files in Oracle ASM and storing Oracle Database files on Oracle Automatic Storage Management Cluster File System (Oracle ACFS).
Note:
Oracle Database and related technologies, such as Oracle Clusterware, no longer support the use of raw (block) storage devices. You must move files to Oracle ASM before upgrading to Oracle Clusterware 12c.
Unless otherwise noted, Oracle Database storage features such as Oracle ASM, Oracle Managed Files, automatic segment-space management, and so on, function the same in Oracle RAC environments as they do in noncluster Oracle database environments.
See Also:
For additional information about these storage features:
Note:
To create an Oracle RAC database using Oracle Database Standard Edition, you must use Oracle ASM for your database storage.