HP 3PAR CIM API Programming Reference

SMI-S View and Paths
Storage arrays usually provide a means for the administrator to specify which initiators can access
what volumes via what logical unit number (LUN). The goal is that a given volume is only accessible
to SCSI commands originated from the specified initiators through specific sets of target ports. The
ability to limit access is called Device Masking. The ability to specify the device address (LUN)
seen by particular initiators is called Device Mapping. In the HP 3PAR Storage System, storage
volumes must be explicitly exported to be visible to hosts or they are not accessible to any host.
A view is a list of logical units exposed through a list of target ports, modeled as
SCSIProtocolController (SPC) with associated StorageVolume, StorageHardwareIDs
(host WWN/iSCSIName), and SCSIProtocolEndPoints (port WWNs/iscsiNames). A path
is a combination of one each: logical unit (volume), initiator port (host port), and target port. An
SPC serves as a collection of paths.
Three kinds of SPCs are supported in the HP 3PAR Storage System environment:
• Matched-Set SPC, its deviceID format is MS:<n:s:p>:<host id>, where <n:s:p> is the
notation of the target port and <host_id> is the system assigned ID of the host where initiator
port(s) reside. For this kind of view, a volume is exposed to the specified host only through
the specified target port. The host can contain multiple initiator ports, hence this kind of view
can have associations to more than one StorageHardwareIDs. This view can also have
associations to multiple StorageVolumes, but only one association to the target port.
◦ Supported ExposePaths Use Cases:
– Create new view
– Add LU to view
– Add initiator port to view — allowed only if the initiator port is zoned together with
the target port
◦ Supported HidePaths Use Cases:
– Remove view
– Remove LU from view
– Remove initiator port from view
• Host-See SPC, its deviceID format is HS:<host id>, where the <host_id> is the system
assigned ID of the host where initiator port(s) reside. For this kind of view, a volume is exposed
to the specified host regardless of the target port. The host can contain multiple initiator ports,
hence this kind of view can have associations to more than one StorageHardwareIDs. This
view can also have associations to multiple StorageVolumes and target ports.
◦ Supported ExposePaths Use Cases:
– Create new view
– Add LU to view
– Add initiator port to view
◦ Supported HidePaths Use Cases:
– Remove view
– Remove LU from view
– Remove initiator port from view
• Port-Present SPC, its deviceID format is PP:<n:s:p>, where <n:s:p> is the notation of the
target port. For this kind of view, a volume is exposed through the specified target port
regardless of the host the port is connected to or zoned with. The host can contain multiple
78 CIM API SMI-S Support