HP StorageWorks XP24000/XP20000 Array Manager Software Reference (T5214-96052, December 2008)
Documentation
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Supported Sys-
tems
LicenseFeature
xpinfo -h accesses the man pages
Open SystemsN/AXPInfo Utility
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You can download these documents from the Manuals page of the HP Business Support Center website: http://www.hp.com/
support/manuals. In the Storage section, click Storage Software and then select a product.
To learn more about HP software products, or to obtain software updates, visit the HP website:
http://www.hp.com
LUN Manager
LUN Manager enables open systems users to define the paths for logical units (LUs). Each LU can be
mapped for access from multiple ports, providing the necessary infrastructure to support alternative
path failover, path load balancing, and clustered systems. You can use LUN Manager to reconfigure
the LUs while the storage system is online so that you can accommodate system configuration changes
and/or fine-tune storage system performance.
LUN Manager allows you to enable LUN Security for specific ports. LUN Security protects mission-critical
data in your storage system from unauthorized access by preventing unauthorized hosts from seeing
or accessing data on a secured LU.
LUN Expansion (LUSE) and Virtual LUN
LUN Expansion (also called Logical Unit Size Expansion, or LUSE) enables you to configure one large
logical volume by combining several small logical devices (LDEVs). The LUSE function allows hosts
that can use only a limited number of LUs per fibre interface to have access to larger amounts of data
by using expanded LUs.
Virtual LUN (also called Custom Volume Size, or CVS) enables you to configure variable-size volumes,
which are usually smaller than normal (fixed-size) volumes. Virtual 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 LUN enables better utilization
of the physical storage capacity of the storage system, and reduces the amount of administrative effort
required to balance I/O workloads. It also boosts remote copy performance by eliminating the need
to copy large volumes of information that are only partially used.
NOTE:
To use Virtual LUN, you need the Open Volume Management license.
NOTE:
Virtual LUN used in conjunction with Cache Residency Manager can achieve greater performance
improvements than when either of these options is used individually. For more information on Cache
Residency Manager, see the
HP StorageWorks XP24000/XP20000 Cache Residency Manager User’s
Guide
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3XP24000/XP20000 Array Manager Software Reference