The hardware acceleration functionality works only if you use an appropriate host and storage array combination.

Use the following hosts and storage arrays:

ESXi version 4.1 or later.

Storage arrays that support storage-based hardware acceleration. ESXi version 4.1 does not support hardware acceleration with NAS storage devices.

On your host, the hardware acceleration is enabled by default. To enable the hardware acceleration on the storage side, check with your storage vendor. Certain storage arrays require that you explicitly activate the hardware acceleration support on the storage side.

When the hardware acceleration functionality is supported, the host can get hardware assistance and perform the following operations faster and more efficiently:

Migration of virtual machines with Storage vMotion

Deployment of virtual machines from templates

Cloning of virtual machines or templates

VMFS clustered locking and metadata operations for virtual machine files

Writes to thin provisioned and thick virtual disks

Creation of fault-tolerant virtual machines