Hitachi 9900 V Series - Manual (Page 16)

PRELIMINARY RELEASE
4 Chapter 1 Overview of LUN Expansion and Virtual LVI/LUN
1.2 Overview of Virtual LVI/LUN
1.2.1 Virtual LVI/LUN Parameters
The Virtual LVI/LUN (VLL) option allows you to configure variable-size volumes, which are
usually smaller than normal (fixed-size) volumes. Virtual LVI/LUN improves data access
performance by reducing logical device contention and host I/O queue times, particularly
when several frequently accessed files are located on the same volume. Virtual LVI/LUN
enables better utilization of the physical storage capacity of the 9900V, and reduces the
amount of administrative effort required to balance I/O workloads.
Virtual LVI/LUN allows you to perform the following types of operations:
Converting a normal volume into free space (see section 4.2.1),
Defining and installing a Virtual LVI/LUN (customized) volume (see section 4.2.2),
Deleting a Virtual LVI/LUN volume (see section 4.2.3), and
Initializing a Virtual LVI/LUN volume (see section 4.2.4).
Figure 1.2 illustrates the available Virtual LVI/LUN functions:
LDEV
LDEV
LDEV
LDEV
LDEV
Space
LDEV
LDEV LDEV
LDEV
VLL
VLL
Volume to Space Install VLL
VLL volume
Normal Volume
Volume Initialize
Figure 1.2 Illustration of Virtual LVI/LUN Operations