You can use the Management Server console to view all disk groups that are managed by an Oracle ASM instance. The information includes the disk group name, its condition, state (mounted or unmounted), associated volumes, storage sizes (allocated, overhead, used), redundancy type, and other attributes.
The information is displayed only when a database is created on any of the disk groups under Oracle ASM. If no database is created on a disk group, the disk group is not listed. To view these disk groups, navigate to the Disk Group tab on the Host page.
To view all disk groups managed by an Oracle ASM instance
In the Management Server console, select Manage > Databases.
In the Databases view, click the Oracle database to view its details.
In the details view, click the ASM tab.
In the ASM table, click the name of the instance to view its details.
Click the ASM Disk Groups tab.