The system starts with no system configuration database.
When powered up, the system discovers all of the Drive Enclosures and creates drive groups to contain the discovered drives.
The system assigns one of the drive groups as the primary drive group.
The system assigns all of the remaining drive groups that it created to a default Storage Domain.
The system then writes the initial configuration to the Persistence volume in the primary drive group.
If the Oracle FS System contains only one drive group, then that drive group is the primary drive group. If the system contains more than one drive group, the system selects one of the drive groups to be primary.
You can change the primary drive group at any time. When assigning a non-primary drive group as the primary, the Oracle FS System migrates the system data to the new primary drive group. The administrator cannot cancel this special data migration.