Hitachi VSP G1000 User Manual page 319

virtual device (VDEV)
A group of logical devices (LDEVs) in a RAID group. A VDEV typically
consists of some fixed volumes (FVs) and some free space. The number
of fixed volumes is determined by the RAID level and device emulation
type.
Virtual LVI/LUN
A custom-size volume whose size is defined by the user using Virtual LVI/
LUN. Also called a custom volume (CV).
virtual volume (V-VOL)
A logical volume in a storage system that has no physical storage space.
Hitachi Thin Image uses V-VOLs as secondary volumes of copy pairs. In
Hitachi Dynamic Provisioning, V-VOLs are referred to as DP-VOLs.
VOL, vol
See volume (VOL or vol).
volume (VOL or vol)
A logical device (LDEV), or a set of concatenated LDEVs in the case of
LUSE, that has been defined to one or more hosts as a single data storage
unit. An open-systems volume is called a logical unit (LU), and a
mainframe volume is called a logical volume image (LVI).
volume pair
See copy pair.
W
write order
The order of write I/Os to the primary volume (P-VOL) of a copy pair. The
data on the secondary volume (S-VOL) is updated in the same order as
on the P-VOL, particularly when there are multiple write operations in one
update cycle. This feature maintains data consistency at the secondary
volume. Update records are sorted in the cache at the remote system to
ensure proper write sequencing.
Hitachi Thin Image User Guide for Hitachi Virtual Storage Platform G Series and F Series
Glossary 319