HP 3PAR InForm OS 3.1.1 Concepts Guide

space allocation, growth increments and other logical disk parameters can be set when you create
a CPG or modified later. HP 3PAR Storage Systems support the following RAID types:
• RAID 0
• RAID 10 (RAID 1)
• RAID 50 (RAID 5)
• RAID Multi-Parity (MP) or RAID 6
For a detailed discussion of logical disks and RAID types, see “Logical Disks” (page 35).
Common Provisioning Groups
A Common Provisioning Group (CPG) is a virtual pool of logical disks that allocates space to virtual
volumes on demand. A CPG allows up to 4,095 virtual volumes to share the CPG's resources.
You can create fully-provisioned virtual volumes and Thinly-Provisioned Virtual Volumes (TPVVs)
that draw space from a CPG's logical disk pool. For more information about CPGs, see “Common
Provisioning Groups” (page 40).
Virtual Volumes
Virtual volumes draw their resources from Common Provisioning Groups (CPGs), and volumes are
exported as Logical Unit Numbers (LUNs) to hosts. Virtual volumes are the only data layer visible
to the hosts. You can create physical copies or virtual copy snapshots of virtual volumes that remain
available if the original base volume becomes unavailable. Before creating virtual volumes, you
must first create CPGs to allocate space to the virtual volumes. For more information about virtual
volumes, see “Virtual Volumes” (page 43).
Fully-Provisioned Virtual Volumes
A fully-provisioned virtual volume is a volume that uses logical disks that belong to a logical disk
pool known as a Common Provisioning Group (CPG). Unlike Thinly-Provisioned Virtual Volumes
(TPVVs), fully-provisioned virtual volumes have a set amount of user space that is allocated for user
data. The fully-provisioned volume size is fixed, and the size limit is 16 TB. For more information
about fully-provisioned virtual volumes, “Fully-Provisioned Virtual Volumes” (page 44).
Thinly-Provisioned Virtual Volumes
A Thinly-Provisioned Virtual Volume (TPVVs) is a volume that uses logical disks that belong to a
logical disk pool known as a Common Provisioning Group (CPG). TPVVs associated with the same
CPG draw space from that pool as needed, allocating space on demand in small increments for
each controller node. As the volumes that draw space from the CPG require additional storage,
the InForm OS automatically creates additional logical disks and adds them to the pool until the
CPG reaches the user-defined growth limit which restricts the CPG’s maximum size. The TPVV
volume size limit is 16 TB. For more information about TPVVs, see “Thinly-Provisioned Virtual
Volumes” (page 44).
NOTE: Creating Thinly-Provisioned Virtual Volumes (TPVVs) requires the HP 3PAR Thin Provisioning
Software license. For more information, see “HP 3PAR InForm OS Software” (page 15).
Physical Copies
A physical copy duplicates all the data from a base volume to a destination volume. The base
volume is the original volume that is copied to the destination volume. The physical copy on the
destination volume becomes available if the original base volume becomes unavailable. Unlike a
virtual copy or snapshot, a physical copy maintains the performance of the base virtual volume.
A physical copy can only be created from a base volume with enough free space to accommodate
writes to that volume during the physical copy operation. In addition, the destination volume must
14 Overview