HP 3PAR VMware ESX Implementation Guide

SN3000B 16 Gb FC switch automatically select the proper fill-word mode 3 as the default
setting.
• McDATA switch or director ports should be in their default modes as G or GX-port (depending
on the switch model), with their speed setting permitting them to autonegotiate.
• Cisco switch ports that connect to HP 3PAR StoreServ Storage ports or host HBA ports should
be set to AdminMode = FX and AdminSpeed = auto port, with the speed set to auto negotiate.
• QLogic switch ports should be set to port type GL-port and port speed auto-detect. QLogic
switch ports that connect to the HP 3PAR StoreServ Storage should be set to I/O Stream Guard
disable or auto, but never enable.
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:
• For information available on host port per target port and max total host ports per array, refer
to the HP 3PAR Feature Availability Matrix documentation available on the HP Single Point
of Connectivity Knowledge (HP SPOCK) website:
HP SPOCK
• I/O queue depth on each HP 3PAR StoreServ Storage HBA model, as follows:
Emulex 4G: 959◦
◦ HP 3PAR HBA 4G: 1638
◦ HP 3PAR HBA 8G: 3276 (HP 3PAR StoreServ 10000 and HP 3PAR StoreServ 7000
systems only)
• The I/O queues are shared among the connected host 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. If this condition occurs, each host should be throttled so that it
cannot overrun the HP 3PAR StoreServ Storage port's queues when all hosts are delivering
their maximum number of I/O requests.
NOTE: When host ports can access multiple targets on fabric zones, the assigned target
number assigned by the host driver for each discovered target can change when the host is
booted and some targets are not present in the zone. This situation may change the device
node access point for devices during a host reboot. This issue can occur with any
fabric-connected storage, and is not specific to the HP 3PAR StoreServ Storage.
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 used as an
alternative to setting host 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 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 HP Priority Optimization (Quality of Service) on HP 3PAR arrays, see the HP
3PAR Priority Optimization technical white paper available on the following website:
HP 3PAR Priority Optimization
Setting Up and Zoning the Fabric 13