Provide information about the disk group on which you want to place the Oracle Cluster Registry (OCR) and voting disk files. You have two options:
Create Disk Group
Select this option to create a new Oracle ASM disk group on available candidate disks.
Use Existing Disk Group
Select this option to select an existing disk group for configuring Oracle ASM.
For example: You can use an existing disk group from a Single Instance High Availability (SIHA) installation to place Oracle Clusterware files (Oracle Cluster Registry and voting disk files), and make that existing disk group available to the cluster. To do this, shut down the SIHA Oracle ASM instance, so that it can be used for configuring clusterware for nodes.
If you do not see an existing diskgroup displayed from the Select Diskgroup list, then click Change Discovery Path, and enter a path where Oracle Universal Installer (OUI) can find the existing disk group.