HP 3PAR Solaris Implementation Guide

Target Port Limits and Specifications
To avoid overwhelming a target port and ensure continuous I/O operations, observe the following
limitations on a target port:
• I/O queue depth on each HP 3PAR StoreServ Storage HBA model, as follows:
QLogic 1G: 512 (HP 3PAR T-Class and HP 3PAR F-Class)◦
◦ QLogic 10G: 2048 (HP 3PAR StoreServ 10000 and HP 3PAR StoreServ 7000 systems
only)
• The I/O queues are shared among the connected host server HBA ports on a first-come,
first-served basis.
• When all queues are in use and a host HBA port tries to initiate I/O, it receives a target queue
full response from the HP 3PAR StoreServ Storage port. This condition can result in erratic I/O
performance on each host server. If this condition occurs, each host server should be throttled
so that it cannot overrun the HP 3PAR StoreServ Storage port's queues when all host servers
are delivering their maximum number of I/O requests.
HP 3PAR Priority Optimization
The HP 3PAR Priority Optimization feature introduced as of HP 3PAR OS version 3.1.2.MU2 is a
more efficient and dynamic solution for managing server workloads and can be utilized as an
alternative to setting host server I/O throttles. Using this feature, a storage administrator is able to
share storage resources more 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 in rare cases.
For complete details of how to use Priority Optimization (Quality of Service) on the HP 3PAR
StoreServ Storage array, see the HP 3PAR Priority Optimization technical white paper available
at the following website:
HP 3PAR Priority Optimization
HP 3PAR OS Persistent Ports
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).
Port shutdown or reset events do not trigger this feature.
Each FC, FCoE, or 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 FC, FCoE, or iSCSI port to
assume the identity (port IP address) 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 multi-pathing 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:
26 Configuring the HP 3PAR StoreServ Storage for iSCSI