The disk group compatibility attributes specify the disk group compatibility settings for Oracle ASM and database instances. These attributes are described under the following topics:
The value for the disk group COMPATIBLE.ASM attribute determines the minimum software version for an Oracle ASM instance that can use the disk group. This setting also affects the format of the data structures for the Oracle ASM metadata on the disk. The format of other file contents is determined by Oracle ASM Dynamic Volume Manager (Oracle ADVM) and the database instance.
For Oracle ASM 12c, 12.1 is the default setting for the COMPATIBLE.ASM attribute when using ASMCA. The default setting is 10.1 when using the SQL CREATE DISKGROUP statement and the ASMCMD mkdg command.
The value for the disk group COMPATIBLE.RDBMS attribute determines the minimum COMPATIBLE database initialization parameter setting for any database instance that is allowed to use the disk group. Before advancing the COMPATIBLE.RDBMS attribute, ensure that the values for the COMPATIBLE initialization parameter for all of the databases that access the disk group are set to at least the value of the new setting for COMPATIBLE.RDBMS.
For example, if the COMPATIBLE initialization parameters of the databases are set to either 11.2 or 12.1, then COMPATIBLE.RDBMS can be set to any value between 10.1 and 11.2 inclusively.
For Oracle ASM 12c, 10.1 is the default setting for the COMPATIBLE.RDBMS attribute when using the SQL CREATE DISKGROUP statement, the ASMCMD mkdg command, and ASMCA.
The database initialization parameter COMPATIBLE enables you to use a new release of Oracle Database, while at the same time guaranteeing backward compatibility with an earlier release. See Oracle Database Reference for more information about the COMPATIBLE initialization parameter.
The value for the disk group COMPATIBLE.ADVM attribute determines whether the disk group can contain Oracle ADVM volumes. The value must be set to 11.2 or higher. Before setting this attribute, the COMPATIBLE.ASM value must be 11.2 or higher. Also, the Oracle ADVM volume drivers must be loaded in the supported environment.
By default, the value of the COMPATIBLE.ADVM attribute is empty until set.
For more information about Oracle ADVM, see "Overview of Oracle ASM Dynamic Volume Manager".