3PAR InForm® OS 2.3.1 Concepts Guide (320-200112 Rev B, February 2010)

2.6
3PAR Storage Concepts and Terminology
3PAR InForm OS Concepts Guide InForm OS Version 2.3.1
2.1.5.3 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 have a user space size at least as large as the user space of the base
volume being copied, and must not be exported.
For additional information on physical copies, see Physical Copies on page 10.6.
2.1.5.4 Virtual Copy Snapshots
A snapshot is a virtual copy of a base volume. The base volume is the original volume that is
copied. Unlike a physical copy which is a duplicate of an entire volume, a virtual copy only
records changes to the base volume. This allows an earlier state of the original virtual volume
to be recreated by starting with its current state and rolling back all the changes that have
been made since the virtual copy was created.
You can make snapshots of: fully-provisioned virtual volumes, TPVVs, physical copies, or
another virtual copy snapshot. Snapshots are created using copy-on-write techniques available
only with the 3PAR Virtual Copy license. Thousands of snapshots of each virtual volume can be
created assuming that there is sufficient storage space available. For additional information on
virtual copies, see Virtual Copy Snapshots on page 10.7.
NOTE: With a 3PAR Remote Copy license, physical copies can be copied from one
InServ Storage Server to another using 3PAR Remote Copy. For additional
information, see the 3PAR Remote Copy User’s Guide.
NOTE: Creating virtual copies requires the 3PAR Virtual Copy license.For more
information, see 3PAR InForm Software on page 2.7.