Enabling VAAI

In order to determine if VAAI is enabled on an ESXi host use the esxcli command or the vSphere Web Client to check if the value of the line “Int Value” is set to 1 (enabled):

All vSphere versions:

esxcli system settings advanced list -o /DataMover/HardwareAcceleratedMove
esxcli system settings advanced list -o /DataMover/HardwareAcceleratedInit
esxcli system settings advanced list -o /VMFS3/HardwareAcceleratedLocking    

vSphere 5.5U2 and later:

esxcli system settings advanced list -o /VMFS3/useATSForHBOnVMFS5

vSphere 6.0 and later:

esxcli system settings advanced list -o /VMFS3/EnableBlockDelete

You will see an output similar to:

Path: /VMFS3/HardwareAcceleratedLocking

Type: integer

Int Value: 1 <- Value is 1 if enabled

Default Int Value: 1

Min Value: 0

Max Value: 1

String Value:

Default String Value:

Valid Characters:

Description: Enable hardware accelerated VMFS locking

Hardware acceleration is enabled by default within ESXi (except EnableBlockDelete) and all options never require any configuration on the array to use out of the box. In the case they were somehow disabled in ESXi, follow these steps to re-enable the primitives:

• To enable atomic test and set (ATS) AKA hardware accelerated locking:

  
  esxcli system settings advanced set -i 1 -o /VMFS3/HardwareAcceleratedLocking
  
  

• To enable hardware accelerated initialization AKA WRITE SAME:

  
  esxcli system settings advanced set --int-value 1 --option /DataMover/HardwareAcceleratedInit
  

• To enable hardware accelerated move AKA XCOPY (full copy):

  
  esxcli system settings advanced set --int-value 1 --option /DataMover/HardwareAcceleratedMove

• In VMware ESXi 5.5 U2 and later, VMware introduced using ATS for VMFS heartbeats. To enable this setting:

  
  esxcli system settings advanced set -i 1 -o /VMFS3/useATSForHBOnVMFS5 

• To enable guest OS UNMAP in vSphere 6.x only:

esxcli system settings advanced set -i 1 -o /VMFS3/EnableBlockDelete 

Figure 3 describes the above steps pictorially using the vSphere Web Client. Go to an ESXi host and then Settings, then Advanced System Settings, and search for “Hardware” or “EnableBlockDelete”, as the case may be, to find the settings.

Figure 3. VAAI advanced options in the vSphere Web Client

Figure 4. Enable Guest OS Unmap in vSphere 6.x