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

virtual volume A virtual storage unit created by mapping data from one or more logical disks.
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 Virtual logical unit number. A VLUN is a virtual volume-LUN pairing expressed as either an active
VLUN or as a 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.
VV template Virtual volume template. The template contains a set of virtual volume parameters that can be
applied to create volumes with the same characteristics using the HP 3PAR Management Console.
write-through
mode
A caching technique in which the completion of a write request is not signaled until data is safely
stored. Write performance with a write-through cache is approximately that of a non-cached
system, but if the data written is also held in cache, subsequent read performance may be
dramatically improved.
WWN World-Wide Name. A unique 64-bit value used to identify Fibre Channel devices on an arbitrated
loop. The WWN consists of a prefix issued by the IEEE to uniquely identify the company and a
suffix that is issued by the company.
zero fill To fill unused storage space with the representation of the character denoting “0”.
zone A unit of physical disk space reserved by a controller node for snapshot or snapshot administration
data. A single zone may occupy space on more than one disk.
96 Glossary