3PAR InForm® OS 2.2.4 Concepts Guide (320-200085 Rev B, March 2009)

GL 14
Glossary
InForm OS Version 2.2.4 3PAR InForm OS Concepts Guide
user privilege levels
Four privilege levels (Super, Edit, Service, and
Browse) allow varying degrees of access to
storage system administrative functions.
user size
The amount of user space in a virtual volume, or
the size of the volume as presented to the host.
user space
The space on a virtual volume that represents
the size of the virtual volume as presented to the
host. For standard base volumes, the user space
holds all user data. For thinly provisioned virtual
volumes, no storage is actually allocated to user
space, so the user space represents the volume's
virtual size. See also virtual size.
V
VCDBA
See 3PAR Virtual Copy DBA.
virtual copy
A snapshot created using the copy-on-write
technique. See also 3PAR Virtual Copy.
virtual copy DBA
See 3PAR Virtual Copy DBA.
virtual copy policy
Determines the course of action should a
volume's snapshot administration space or
snapshot data space become depleted. See also
stale snapshots and no stale snapshots.
virtual size
The size that the volume presents to the host.
For standard base volumes, the virtual size is
equal to the user space. For thinly provisioned
virtual volumes, no storage is actually allocated
to user space, so the virtual size is determined by
whatever value is assigned to the user space. See
also user space.
virtual volume
A virtual storage unit created by mapping data
from one or more logical disks. See also logical
disk, mapping.
virtual volume backup nodes
The controller nodes that take over for the
virtual volume master node if the virtual volume
master node fails.
virtual volume master node
The controller node that is responsible for a
virtual volume from its creation to its deletion.
When the system builds a virtual volume, the
system begins with the logical disk connected to
the master node.
virtual volume region
A subdivision of a virtual volume. The size of a
region is always a multiple of 32 MB.
VLUN
Stands for virtual-LUN. A VLUN is a virtual
volume-LUN pairing expressed as either an active
VLUN or as a VLUN template. See also active
VLUN, VLUN template.
VLUN template
A rule that sets up the association between the
name of the virtual volume and a LUN-host, LUN-
port, or LUN-host-port combination. The three
types of VLUN templates are host-sees, port-
presents, and matched-set. See also active VLUN,
LUN.
VV
See virtual volume.