HP 3PAR VMware ESX Implementation Guide

You can also use the esxcli command to set these values on a per-device basis. If both options
(the esxcli and the advanced parameters) are used, the per-device values take precedence.
To set QFullSampleSize and QFullThreshold on a per-device level, use theesxcli command:
# esxcli storage core device set --device device_name -q Q -s S
The settings do not require a reboot to take effect and are persistent across reboots.
You can retrieve the values for a device using the corresponding list command:
# esxcli storage core device list
The command supports an optional --device parameter:
#
esxcli storage core device list --device device_name
ESX/ESXi 4.1, ESXi 5.x Additional Feature Considerations
ESX/ESXi 4.1 and ESXi 5.x introduce new features related to storage I/O control and integration
with storage arrays. HP recommends using SIOC and vStorage APIs for Array Integration (VAAI)
with ESX/ESXi 4.1, ESXi 5.x - HP 3PAR StoreServ Storage configurations.
NOTE: This section about VAAI and new features applies to all connectivity types: FC, FCoE and
iSCSI.
Storage I/O Control
The SIOC feature allows a new level of monitoring and control of I/O from individual virtual
machines to an HP 3PAR StoreServ Storage array at the datastore level and across ESX/ESXi hosts
in a VMware cluster.
More informationabout the SIOC feature and considerations for its deployment may be found in
the VMware technical white paper, Storage I/O Control Technical Overview and Considerations
for Deployment:
VMware
vStorage APIs for Array Integration (VAAI)
In partnership with VMware, HP has developed an ESX/ESXi 4.1 plug-in that enables a new set
of SCSI commands to be used by ESX/ESXi 4.1 in conjunction with HP 3PAR StoreServ Storage.
VMware refers to this newly incorporated set of SCSI commands as the "primitives".
ESX extensions that make use of these primitives are collectively referred to as vStorage APIs for
Array Integration (VAAI). The VMware primitives allow an ESX/ESXi host to send virtual machine
operations to storage hardware at a meta level instead of at the traditional data level. This reduces
operational latency and traffic on the FC fabric/iSCSI network. Some of these primitives allow the
storage hardware to participate in block allocation and de-allocation functions for virtual machines.
These primitives are also known as hardware offloads.
A brief description of the "primitives":
• Full Copy (XCOPY) enables the storage array to make full copies of data within the array
without having to have the ESX host read and write the data. This offloads some data copy
processes to the storage array.
• Block Zeroing (WRITE-SAME) enables the storage array to zero-out a large number of blocks
within the array without having to have the ESX host write the zeros as data and helps expedite
50 Configuring the Host for a Fibre Channel Connection