HP 3PAR StoreServ Concepts Guide: HP 3PAR OS 3.1.3

allow for continued growth of the volume. When a TPVV reaches approximately 80% of capacity,
the incremental benefit of capacity savings versus accelerating performance is weighted towards
performance. In addition, converting volumes from thinly-provisioned to fully-provisioned can free
up thinly-provisioned capacity for other TPVVs. Similarly, if an FPVV storage space is largely unused,
you might choose to convert it to a TPVV to save storage space.
Converting remote copy virtual volumes and virtual volumes that contain snapshots is not supported.
You can, however, convert virtual volumes with snapshots and create a new virtual volume with a
new WWN that contains the original LDs and snapshots.
Virtual volumes can be converted by using the HP 3PAR CLI or the HP 3PAR Management Console.
See the HP 3PAR Command Line Interface Administrator’s Manual and the HP 3PAR Management
Console Online Help for instructions on performing these tasks.
Converting volumes from thin to full requires the HP 3PAR Dynamic Optimization license.
Converting volumes from full to thin requires the HP 3PAR Dynamic Optimization Software license
and HP 3PAR Thin Provisioning Software license.
For more information, see “HP 3PAR Software” (page 10).
Physical Copies
A physical copy is a full copy of a volume. A physical copy duplicates all the data from one original
base volume to a destination volume. Any changes to either volume causes them to lose
synchronization with each other, which is corrected by resynchronizing the two volumes as described
in the HP 3PAR Command Line Interface Administrator’s Manual and the HP 3PAR Management
Console Online Help. No special license is required to create a physical copy of a volume.
Physical copies can be created and managed in groups to reduce the number of management
tasks. You can create a consistent group of physical copies from a list of virtual volumes, and group
physical copies into autonomic groups that are managed as s single physical copy.
A physical copy be created only from a volume with enough free space to accommodate writes
to that volume during the physical copy operation. In addition, the destination volume must meet
the following conditions:
• It must have snapshot space associated with it.
• It must have at least as much user space as the volume being copied.
• It must not be exported to a host.
For the maximum number of physical copies that can be created with your specific system
configuration, go to the SPOCK website:
http://www.hp.com/storage/spock
NOTE: If the base volume and destination volume are both TPVVs, only the space that is actually
used is copied. See “Overview” (page 7) for additional information on TPVVs.
Virtual Copy Snapshots
A virtual copy is a snapshot of a virtual volume. You can make virtual copies of base volumes,
physical copies, or other virtual copies. Virtual copies are created by using copy-on-write techniques
that are available only with the HP 3PAR Virtual Copy Software license. Unlike a physical copy,
which duplicates the entire base volume, a virtual copy records only the changes to the original
volume. This allows an earlier state of the original volume to be recreated by starting with the
current state and rolling back all of the changes that have been made since the virtual copy was
created.
The system allows you to make a maximum of 500 virtual copies of a base volume. Up to 256
virtual copies can be read/write copies. The maximum number of virtual copies that can be created
on a system is determined by the system configuration. For the maximum number of virtual copies
that can be created with your specific system configuration, go to the HP SPOCK website:
Physical Copies 47