6.7

Hardware Acceleration Requirements
The hardware acceleration functionality works only if you use an appropriate host and storage array
combination.
Table 24‑1. Hardware Acceleration Storage Requirements
ESXi Block Storage Devices NAS Devices
ESXi Support T10 SCSI standard, or block
storage plug-ins for array integration
(VAAI)
Support NAS plug-ins for array integration
Note If your SAN or NAS storage fabric uses an intermediate appliance in front of a storage system that
supports hardware acceleration, the intermediate appliance must also support hardware acceleration and
be properly certified. The intermediate appliance might be a storage virtualization appliance, I/O
acceleration appliance, encryption appliance, and so on.
Hardware Acceleration Support Status
For each storage device and datastore, the vSphere Client display the hardware acceleration support
status.
The status values are Unknown, Supported, and Not Supported. The initial value is Unknown.
For block devices, the status changes to Supported after the host successfully performs the offload
operation. If the offload operation fails, the status changes to Not Supported. The status remains
Unknown if the device provides partial hardware acceleration support.
With NAS, the status becomes Supported when the storage can perform at least one hardware offload
operation.
When storage devices do not support or provide partial support for the host operations, your host reverts
to its native methods to perform unsupported operations.
Hardware Acceleration for Block Storage Devices
With hardware acceleration, your host can integrate with block storage devices, Fibre Channel or iSCSI,
and use certain storage array operations.
ESXi hardware acceleration supports the following array operations:
n
Full copy, also called clone blocks or copy offload. Enables the storage arrays to make full copies of
data within the array without having the host read and write the data. This operation reduces the time
and network load when cloning virtual machines, provisioning from a template, or migrating with
vMotion.
n
Block zeroing, also called write same. Enables storage arrays to zero out a large number of blocks to
provide newly allocated storage, free of previously written data. This operation reduces the time and
network load when creating virtual machines and formatting virtual disks.
vSphere Storage
VMware, Inc. 316