HP StorageWorks Windows Kit V3.0B for Enterprise Virtual Array Installation and Configuration Guide (AA-RUGZB-TE, October 2003)

Understanding the Enterprise Virtual Array
17Windows Kit V3.0B for Enterprise Virtual Array Installation and Configuration Guide
SAN Considerations
Ensure that your SAN components are all supported for use with the Enterprise
Virtual Array. Design your SAN with an HP standard topology or by following
the HP SAN design rules for creating custom topologies. Refer to the HP
StorageWorks SAN Design Reference Guide for help with topology rules. The
most up-to-date version of this guide can be found on the HP website at
http://h18004.www1.hp.com/products/storageworks/san/doc ume ntation.html .
Multiple-Path Support
Enterprise Virtual Array requires a multiple-path environment. Each host you
attach must have supported multiple pathing software (see the platform-specific
release notes for the supported versions).
Host Presentation Compared with Enterprise Modular Array
In previous technology (Enterprise Modular Array family), the term virtual disks
was used to describe what is presented to the host. Those virtual disks were
derived from logical slices of storage, using specific sets of physical disks
designed by the administrator.
With Enterprise Virtual Array, the disk pool used to derive virtual disks can be up
to the entire set of physical disks available to the controllers. You do not need to
be concerned with which physical disks are used to create the virtual disks.
However, you do make decisions regarding disk groups, which are the number of
physical disks used, and redundancy level.
Virtual disks presented to the host servers with either technology appear like any
other SAN disk resource. From the server side, there is no difference. Hosts access
the virtual disks as a Logical Unit Number (LUN) with capacity knowledge.