HP StorageWorks SAN Virtualization Services Platform SMI-S User Guide (5697-0209, April 2010)

Object model diagram
Object model summary
The Extent Composition Subprofile demonstrates how the storage virtual disk is constructed from its
constituent elements by modeling the hierarchy of extents between the primordial extents and the
storage virtual disk itself. Elements of the hierarchy are related to each other using associations marking
the type of construction as either a composition or decomposition.
A composition is a CompositeExtent related to dependent extents using a CompositeExtentBasedOn
association. This association demonstrates that one extent is constructed from a group of dependent
extents.
A decomposition is a StorageExtent related to underlying extents using a BasedOn association. The
StorageExtent represents a span of virtual storage that may be split (decomposed) among other
elements. In the case where a storage extent is partially used to construct other extents, the unused
remainder must be modelled using a BasedOn association to a remainder extent.
The Extent Composition Subprofile mandates that storage extents be associated to an appropriate
storage pool defined in the Block Services package.
Additional details
Traverse the virtualization hierarchy of virtual disk
Given a virtual disk, a client may wish to discern the Quality of Service, and storage pool association
of each element comprising the virtual disk.
• A client starts with a virtual disk element, HPSVSP_VirtualDisk (from Block Services).
Extent Composition Profile118