HP Matrix Operating Environment Software - Manual (Page 65)

3PAR calculation (CPG based pools) SPM capacity value
Calculated as the sum of all volumes’ subscribed capacities.
Hence SPM reports logical capacity. Subscribed capacity
The difference between the CPG’s physical capacity and
its committed capacity. Available capacity
Volume capacity
SPM tracks capacity and committed capacity for volumes, where capacity is the overall capacity
of the volume in bytes and committed capacity is the number of bytes that have actually been
reserved for the volume.
Capacity in SPM maps to the usable capacity of the volume accounting for RAID overhead and
administrative space. For thinly provisioned volumes, this may be greater than the committed
capacity. SPM’s committed capacity for thinly provisioned volumes the number of provisioned
blocks times the block size. For thickly provisioned volumes, the committed capacity is the same
as the capacity.
The 3PAR array reports all storage capacities in binary units proposed by the International
Electrotechnical Commission (IEC) instead of the International System of Units (SI) decimal units.
As an example, 20GiB in binary units would be equivalent to 21.47GB in decimal units. Matrix
customers will notice a capacity reporting difference when using the 3PAR storage array if not
using SPM. SPM helps the customer address this unit conversion issue by allowing the customer to
set the preferred capacity reporting units. We recommend that the preferences in SPM be set to
decimal units.
Understanding 3PAR Storage System volume creation/growth
During storage service provisioning, a set of service requirements are drawn from the storage
service template and additional requirements. SPM uses these requirements to select a set of
candidate volumes to offer for service fulfillment. SPM uses capacity information from the array,
both for volumes and storage pools, to generate the candidates.
The candidates may include existing volumes of the appropriate size, existing volumes that would
need to grow, or as yet uncreated volumes. If a given candidate volume doesn’t match the service’s
requirements exactly, provisioning automation is required to make the change on the array to fulfill
the service. This automation is divided up into discrete steps, like “create a volume” or “grow a
volume” as well as “update a volume’s presentation settings”.
SPM uses the importing credentials and SMI-S protocol to access the array to make the automated
changes.
Understanding 3PAR Storage System virtual domains
On 3PAR Storage Systems, multi-tenancy is implemented with virtual domains. Logical resources
(hosts, volumes, and users) can be assigned to a virtual domain. Within the virtual domain, the
users are assigned permissions: browse, edit, or super. Whether or not they are part of a virtual
domain, all volumes and hosts on the array are considered part of the array-level domain called
All.
When importing an array, the Storage Administrator selects a user. The array that is discovered
will present only those resources that are visible to the selected user. If the user belongs only to
domain All, all resources are visible; if the user belongs to a virtual domain, only those resources
in the domain to which the user belongs are visible.
IMPORTANT: SPM does not currently support virtual domains. When importing a 3PAR Storage
System, select only users that have permission level super and belong to the All virtual domain.
If after importing the 3PAR Storage System, a storage administrator moves hosts to a specific virtual
domain using the 3PAR CLI and/or Graphical User Interface, subsequent automation in SPM might
fail.
For more information on virtual domains, refer to the array user guide.
Understanding 3PAR Storage System volume creation/growth 65