Primary Drive Group Description

The primary drive group is the drive group in an Oracle FS System that contains the system-wide Persistence volume. The Persistence volume is the internal name of the volume that contains the system configuration database. The system contains one primary drive group.

If only one drive group exists, the 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. The Oracle FS System places the primary drive group on the lowest Storage Class in the system. If you add Drive Enclosures to the system that are a lower Storage Class than the existing classes, the system automatically migrates the primary drive group to the new lowest Storage Class. The system then migrates the system configuration database that is contained in the Persistence volume to the newly assigned primary drive group.

Note: Assign the primary drive group to a lower Storage Class, such as Capacity hard disk drive (HDD).

If a nonprimary drive group becomes the primary drive group, the system migrates the system data to the new primary drive group. The administrator cannot cancel this special data migration.

For a new Oracle FS System, or after a system reset, the following sequence occurs:

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 default primary drive group contains drives with the lowest Storage Class in the system, such as Capacity Disk.
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 more Drive Enclosures are added to the system, and those Drive Enclosures contain a lower Storage Class, the system automatically designates one of the drive groups in the new Drive Enclosure as primary. The system then migrates the system configuration database contained in the Persistence volume to that new, primary drive group.