HP 3PAR Solutions Software for vSphere - Manual (Page 14)

2.4 Package Contents
3PAR VAAI Plug-in 1.1.0 for VMware vSphere 4.1 Users Guide
Block Zeroing Increases performance and efficiency by eliminating the writing of zeros as data
by the host for the purpose of "cleaning" space for a VMDK. Using the WRITE-SAME
command, VMware now transfers the overhead associated with these writes to the storage
array by instructing the storage array to assume the burden of writing the zeros on these
newly allocated blocks.
3PAR arrays then takes this WRITE SAME command a step further when the blocks associated
with the VM are initialized. 3PAR's ASIC and its Thin Persistence software recognize the zeros
as they are written by the WRITE SAME command thus reducing system workload.
Since 3PAR tracks which blocks on its array are zeroed out and which ones have data in them,
3PAR only needs to zero out the blocks with data in them. Blocks of data that do contain zeros
are unmapped so no write penalty is incurred on the 3PAR system.
2.3 Package Contents
You can download the installation package from the following location:
http://www.3par.com/services/download.html
2.4 System Requirements
The following components are required:
■ VMware ESX 4.1 or ESXi 4.1.
■ VMware vSphere Infrastructure Management 4.1 (vCenter, vClient).
■ Additionally, for package installation / deinstallation:
◆ For ESX / ESXi
◆ VMware Update Manager plug-in (VUM) or vSphere CLI (vCLI)
◆ For ESX
◆ ESX Service Console