HP 3PAR Citrix Implementation Guide

In addition, some HP switches, such as the HP SN8000B 8-slot SAN backbone director switch,
the HP SN8000B 4-slot SAN director switch, the HP SN6000B 16 Gb FC switch, or the HP
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.
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:
• Maximum of 32 host ports per HP 3PAR StoreServ Storage port, with a maximum total of
1,024 host ports per HP 3PAR StoreServ Storage.
• 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 Storage 10000 and HP 3PAR StoreServ
Storage 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 in HP 3PAR OS 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 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 HP 3PAR Priority Optimization (Quality of Service) on HP 3PAR StoreServ
Storage arrays, see the HP 3PAR Priority Optimization technical whitepaper, available at the HP
website:
HP 3PAR Priority Optimization
12 Configuring the HP 3PAR StoreServ Storage for Fibre Channel