HP StorageWorks LUN Configuration and Security Manager XP user guide for the XP12000/XP10000/SVS200 (T1714-96008, June 2006)

LUN Configuration and Security Manager XP user guide for the XP12000/XP10000/SVS200 127
7 Overview of Volume Manager and Custom Volume
Size
Volume Manager and Custom Volume Size (CVS) are functions for open systems and mainframe systems.
To use these functions, you need the software called HP StorageWorks LUN Configuration and Security
Manager XP.
This chapter describes Volume Manager and CVS.
Overview of Volume Manager
This section describes the Volume Manager function and configuration of LUSE volumes (expanded LUs).
Volume Manager operations include the following:
Viewing concatenated parity groups” on page 151
Creating LUSE volumes” on page 151
Releasing LUSE volumes” on page 153
Changing LUSE capacities” on page 153
Volume Manager function
The Volume Manager function is applied to open-system logical volumes and enables you to configure
one large logical volume by combining several small LDEVs. The Volume Manager function allows hosts
that can only use a limited number of logical units (LUs) per fibre interface to access larger amounts of
data using expanded LUs.
Figure 78 shows the LUSE configuration. By using the Volume Manager function, you can combine
several logical devices (LDEVs) or volumes into one large logical volume. The configured LDEV’s size can
be expanded up to 36 times the size of the original LDEV. The ID of the logical volume defined as the
large logical volume is represented by the smallest LDEV ID (assigned to the top LDEV). The host
recognizes the expanded logical volume as one representative LDEV. As long as the number of LDEVs
combined into one large logical volume does not exceed the specified limit (see ”Volume Manager
guidelineson page 128), you can arbitrarily select any LDEVs as the volumes to combine, regardless of
their size (or capacity) or whether or not they are on the same Control Unit (CU). The Volume Manager
function also allows you to combine several LDEVs and a LUSE volume (combined LDEVs) into one LUSE
volume, or combine LUSE volumes together into one LUSE volume.