ESXi Integrated feature support

ESX vStorage APIs for Array Integration (VAAI) is a feature introduced in ESXi/ESX 4.1 that provides hardware acceleration functionality. It allows the host to offload specific virtual machine and storage management operations to compliant storage hardware. With the storage hardware's assistance, the host performs these operations faster, and consumes less CPU, memory, and storage fabric bandwidth.

VAAI uses these fundamental operations:

  • Atomic Test & Set (ATS), which is used during creation and locking of files on the VMFS volume
  • Clone Blocks/Full Copy/XCOPY, which is used to copy or migrate data within the same physical array
  • Zero Blocks/Write Same, which is used to zero-out disk regions
  • Thin Provisioning in ESXi 5.x and later hosts, which allows the ESXi host to tell the array when the space previously occupied by a virtual machine (whether it is deleted or migrated to another datastore) can be reclaimed on thin provisioned LUNs.
  • Block Delete in ESXi 5.x and later hosts, which allows for space to be reclaimed using the SCSI UNMAP feature.

The VxFlex OS supported VAAI features are:

  • Atomic Test & Set (ATS)
  • Zero Blocks/Write Same
  • Thin Provisioning in ESXi 5.x and later hosts
  • Block Delete in ESXi 5.x and later hosts

The following output is an example of typical output:

esxcli storage core device vaai status get -d
eui.7dbf14034834bbe01bf7e55800000002
eui.7dbf14034834bbe01bf7e55800000002
VAAI Plugin Name:
ATS Status: supported 

Clone Status: unsupported This means that Clone Block/Full Copy/Xcopy is not supported.

Zero Status: supported This means that write same is supported.

Delete Status: supported This means that UNMAP is supported.

Note: Thin provisioning is not shown in VAAI output.