To release the disks currently managed by Oracle ASM Filter Driver, follow these steps:
From Targets menu, select All Targets.
On the All Targets page, select any target of type Automatic Storage Management.
On the target home page, from Automatic Storage Management menu, select Configuration Parameters.
On the Configuration page, click Manage Disk Provisioning. The ASM Filter Driver Page is displayed.
From the Provisioned Disks table, select one or more disks, then click Release.
In the Release Provisioned Disks dialog box, click Yes to release the disks
After the disks are released, they are removed from the Provisioned Disks table. They instead appear in the Disks available for provisioning table as a candidate eligible to be provisioned.