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

8 Storage Server Asymmetry Profile
Profile introduction
This VSM server profile supports the SMI-S 1.4 Storage Server Asymmetry Profile. The provided
functionality encompasses the management of the primary and active relationship between virtual
disks, snapshots, groups, and group snapshots and the Data Path Modules in the VSM server.
The following profiles are related to this one:
• The Storage Server Asymmetry Component Profile extends the Multiple Computer System Component
Profile.
Functional description
This profile provides for managing the primary and active assignment of VirtualDisks, Snapshots, and
Groups to a StorageProcessor (Data Path Module):6.1.4.1.311.
• The set of VirtualDisks, Snapshots, Groups that are assigned to a DPM group can be discovered.
• A VirtualDisk, Snapshot, or Group's primary assignment can be reassigned to a DPM in a DPM
pair. Note that initial assignment is outside the scope of this profile.
The profile provides for discovering whether a VirtualDisk, Snapshot, or Group can be accessed
through a target port on a Data Path Module. When the DPM is healthy, this corresponds to the
"owned"/"not owned" Peripheral Qualifer result from the SCSI Inquiry command to the port. The term
"target port" when used in this profile means the SCSI target port aspect of the physical port. For
Fibre Channel these are the same.
The profile also presents the access to active and non-active virtual disks when a DPM with target
ports is healthy. For this product, this is "Active-Optimized" (full bandwidth) for virtual disks, snapshots,
and groups active for "This" DPM and "Standby" (no access) for virtual disks, snapshots, and groups
active for the "Other" DPM.
Object model
Object model overview
Note that the base SMI Storage Server Asymmetry Profile (from which this profile is extended) and
the VSM both use the same "Primary" and "Active" terms but to refer to differing behavior. For this
reason, and to support the VSM functionality, this profile is a vendor-extension of the SMI base profile
in which no new classes are added. Instead the original semantics of the StorageResourceLoadGroup
class have been generalized so that instead of one LoadGroup for each Storage Processor in which
the LoadGroup aggregrates all VirtualDisks and Snapshots that are "Primary" for that storage processor,
there is instead a LoadGroup for each individual VirtualDisk, Snapshot, or Group so that the ability
is modeled for each such virtual device to be individually primary or active on a Data Path Module
(storage processor).
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