HP Matrix Operating Environment Software - Manual (Page 75)

Understanding P9000/XP disk array presentation, mapping, and masking
In the HP P9000/XP disk array, volumes are presented through FC host ports, which SPM calls
target ports, and host groups. A host group is a collection of initiator endpoints. Each initiator
endpoint is a represented as a WWN. A host group is used to explicitly define a mapping and
masking relationship between a specific volume and initiators included in the host group.
Hierarchically, host groups are defined under array target ports. This implies that an initiator can
exist in multiple host groups, but under different array target ports. Also, host group names are
case sensitive, i.e. Host1 and host1 are treated as two different host groups by P9000/XP and
SPM.
These host groups are called “host entries” in SPM, which tracks them as collections of initiator
endpoints. When a P9000/XP array is imported into SPM, its host group details are discovered
and equivalent host entries are created in SPM's catalog. During storage service provisioning
automation, presentation update requests may reference hosts that map to the P9000/XP host
WWNs or new collections of initiator endpoints. SPM uses the host group's initiator endpoint
addresses to relate the hosts to existing WWNs if possible. The presentation update may potentially
cause an un-present operation on the volume to clear its current presentation setting (i.e. to mask
the old presentation). Then, if necessary, host groups (WWNs) are created on the array on all the
specified target ports. Finally, the provider updates the results of the presentation operation to map
the volume to the appropriate host group. P9000/XP allows more than one initiator endpoints be
grouped in a host group.
SPM does not populate the “nickname” attribute of a host WWN in a host group.
Working with P9000/XP disk array host modes
HP P9000/XP disk arrays support a variety of host modes that depend on the operating system.
SPM supports creation of the following host modes for P9000/XP disk array.
SPM host mode P9000/XP host mode
Windows / Windows 2008 Windows
Linux Standard
HPUX HPUX
Vmware Vmware
OpenVMS OpenVMS
Creating hosts on a P9000/XP disk array
When SPM attempts to present a volume to an initiator, it first probes the array to detect whether
this initiator is known to the array. If it is not, a new host group is created for that initiator, under
required (multiple) target ports. When hosts are created by Matrix, the host name will be prefixed
with the string “LSM_”. If no host name is specified in the service requirements or if there is a
naming conflict with existing host groups, the name will be of the form “SPM_<time in milliseconds>”
or “SPM_<unique identifier>. See table below for more detailed information. If SPM presents a
volume to an initiator that is already included in a host group on the array, and if that initiator
belongs to a multiple-initiator host, then all initiators for that host will be mapped to the volume.
This could potentially result in a non-conformant service.
HP P9000/XP disk array has constraints for maximum length of host group name that can be
created on the array. SPM supports following limits for maximum length for host group name.
Default host group name if conflict
encountered
Maximum length supported in SPM Array model
SPM_<time_in_ms> 64 characters P9500
SPM<unique_identifier> 16 characters * XP24000/20000
Understanding P9000/XP disk array presentation, mapping, and masking 75