Since BVQ 3.5.2 a new object type has been implemented to support child mdisk groups
In SVC Version 7.4 IBM offered the possibility to devide mdisk groups (storage pool) into smaller units - child mdisk groups (child pools). BVQ version 3.5 added the functionality to support this feature.
MDg = MDisk Group | CMDg = Child MDisk Group
Child pools will give the admin new possibilities to tailor capacities and performance to their needs. But most likely badly planned use of child pool will be a source of performance issues and the question which volume to place into which pool is something where analysis is needed.
For this it is a goof thing that BVQ can now display the topology, capacities and performance inside child pools
There are often cases where you want to sub-divide a storage pool (or managed disk group) but maintain a larger number of mdisks in that pool. Child pools are logically similar to storage pools, but allow you to specify one or more sub divided child pools. Quotas and warnings can be set independently per child pool.