HP Storage Provisioning Manager (SPM) version 2.3 User Guide

properties in SPM or HP P6000 Command View Software. In the P6000/EVA, RAID levels are
assigned to each volume. Allocated capacity grows when:
• A fully provisioned volume is created, in which case necessary disk space is allocated to the
disk group to account for the full size of the volume and RAID overhead.
• A thin volume is allocated, a small amount of disk space is allocated to cover administrator
space requirements
• When a host writes to a thinly provisioned volume.
P6000/EVA disk arrays cannot create a thinly provisioned disk of more than 32TB of capacity.
Additionally, there is also an available thin volume capacity that is calculated which is different
from the available capacity for thick provisioned volumes. Both these capacities are taken into
consideration while listing candidates for creating/growing a thin provisioned volume.
Understanding P6000/EVA storage system presentation, mapping, and
masking
The P6000/EVA storage system provides a presentation model for managing host access to
volumes. This model allows for explicitly defined mapping and masking, based on specific Vdisk
and host initiators. This presentation model allows a volume to be accessed by initiators on available
controller host ports.
The preferred controller may be automatically configured by the P6000/EVA system or may be
set to a preferred controller by the administrator. Internally, SPM tracks hosts as collections of
initiator endpoints. When a P6000/EVA array is imported into SPM, its host port WWNs are
found and equivalent host port entries are created in SPM's catalog. During storage service
provisioning automation, presentation update requests may reference hosts that map to the
P6000/EVA host entry or new collections of initiator endpoints.
SPM uses the hosts' initiator endpoint addresses to relate the hosts to an existing host entry on the
array if possible. The presentation update may potentially cause an unpresent operation on the
volume to clear its current presentation setting (i.e. to mask the old presentation). Then, if necessary,
host entries are created on the array.
Finally, the update results in a presentation operation to map the volume to the appropriate host.
The P6000/EVA storage system constrains host entries, disallowing a particular initiator endpoint
address to exist in more than one host entry. This means that two volumes presented to the same
initiator endpoint reference the same host entry. This means that a particular requested presentation
change could affect presentation for another volume if the request would modify the host entry.
SPM looks for these kind of side effects and blocks them.
Working with P6000/EVA storage system host modes
Working with P6000/EVA storage systems, there is a one-to-one relationship between SPM host
modes and P6000/EVA’s supported host modes, with one exception. Because the P6000/EVA
does not support a separate host mode for Windows 2012, specifying a host operating system
of Windows 2012 will be mapped to the P6000/EVA’s Windows 2008 host mode.
NOTE: When SPM presents a volume on an EVA array to a Windows 2012 host, it uses Windows
2008 host mode on the array.
Creating hosts on a P6000/EVA storage system
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 is created for that initiator. The name
given to that host “LSM_” followed by the WWN of the initator if created by Matrix or “SPM_”
followed by the WWN of the initiator if created within SPM. SPM can show presentations that
contain hosts with multiple initiator ports, but when creating hosts, SPM always creates a host with
a single initiator port. If SPM must present a volume to an initiator that is already referenced on
the array, and if that initiator belongs to a multiple-initiator host, then all initiators for that host are
mapped to the volume. This could potentially result in a nonconformant service.
Understanding P6000/EVA storage system presentation, mapping, and masking 77