HP 3PAR VMware ESX Implementation Guide

HP 3PAR Priority Optimization for iSCSI
The HP 3PAR Priority Optimization feature introduced in HP 3PAR OS 3.1.2.MU2 is an efficient
and dynamic solution for managing server workloads and can be used as an alternative to setting
host I/O throttles. Using this feature, a storage administrator can share storage resources effectively
by enforcing quality of service limits on the array. No special settings are needed on the host side
to obtain the benefit of HP 3PAR Priority Optimization although certain per target or per adapter
throttle settings may need to be adjusted. For complete details on how to use HP 3PAR Priority
Optimization (Quality of Service) on HP 3PAR StoreServ Storage arrays, see the HP 3PAR Priority
Optimization technical whitepaper (HP document #4AA4-7604ENW) on the HP website:
HP 3PAR Priority Optimization
HP 3PAR OS Persistent Ports for iSCSI
The HP 3PAR OS Persistent Ports (or virtual ports) feature minimizes I/O disruption during an
HP 3PAR StoreServ Storage online upgrade or node-down event (online upgrade, node reboot,
or cable pull test). Port shutdown or reset events do not trigger this feature.
Each iSCSI target storage array port has a partner array port automatically assigned by the system.
Partner ports are assigned across array node pairs.
HP 3PAR OS Persistent Ports allows an HP 3PAR StoreServ Storage iSCSI port to assume the identity
of a failed port while retaining its own identity. Where a given physical port assumes the identity
of its partner port, the assumed port is designated as a persistent port. Array port failover and
failback with HP 3PAR OS Persistent Ports is transparent to most host-based multipathing software,
which can keep all of its I/O paths active.
NOTE: Use of HP 3PAR OS Persistent Ports technology does not negate the need for properly
installed, configured, and maintained host multipathing software.
For a more complete description of the HP 3PAR OS Persistent Ports feature, its operation, and a
complete list of required setup and connectivity guidelines, see:
• The HP Technical white paper HP 3PAR StoreServ Persistent Ports (HP document
#F4AA4-4545ENW)
This document is available on the following HP SC website:
HP Support Center
• The HP 3PAR Command Line Interface Administrator’s Manual, “Using Persistent Ports for
Nondisruptive Online Software Upgrades”
This document is available on the HP Storage Information Library
www.hp.com/go/storage/docs
iSCSI
HP 3PAR OS Persistent Ports Setup and Connectivity Guidelines for iSCSI
Starting with HP 3PAR OS 3.1.3, the HP 3PAR OS Persistent Ports feature is supported for iSCSI.
The HP 3PAR OS Persistent Ports feature is enabled by default for HP 3PAR StoreServ Storage
iSCSI ports during node-down events.
Follow the specific cabling setup and connectivity guidelines for HP 3PAR OS Persistent Ports to
function properly.
A key element for iSCSI connectivity is that partner ports must share the same IP network.
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