+=item B<disk_physical>: report 'disk_physical' statistic for disk device.
+B<Note>: This statistic is only reported for disk devices with 'source'
+property available.
+
+=item B<disk_allocation>: report 'disk_allocation' statistic for disk device.
+B<Note>: This statistic is only reported for disk devices with 'source'
+property available.
+
+=item B<disk_capacity>: report 'disk_capacity' statistic for disk device.
+B<Note>: This statistic is only reported for disk devices with 'source'
+property available.
+