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Disabling the VAAI functionality in ESXi/ESX (1033665)

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This article provides steps to disable the vStorage APIs for Array Integration (VAAI) functionality in ESXi/ESX. You may want to disable VAAI if the storage array devices in the environment do not support the hardware acceleration functionality or are not responding correctly to VAAI primitives.

For information on VAAI support in a given storage array or required firmware levels, contact the storage array vendor.


Note: If you are running a VMware vSAN environment, it is important that Hardware Assisted Locking (ATS) is not disabled.
Disabling VAAI when using Block storage
To disable VAAI in ESXi/ESX, you must modify these advanced configuration settings:

  • HardwareAcceleratedMove
  • HardwareAcceleratedInit
  • HardwareAcceleratedLocking
To check the current value of the configuration settings:

Note: Replace OptionName with one of the configuration setting names.

  • Using the vSphere CLI:

    vicfg-advcfg connection_options -get OptionName

  • Using the PowerCLI:

    Get-VMHostAdvancedConfiguration -VMHost Hostname -Name OptionName

  • Using SSH/DCUI:

    # esxcfg-advcfg --get OptionName


    # esxcli system settings advanced list --option OptionName

    For example: # esxcli system settings advanced list --option=/VMFS3/HardwareAcceleratedLocking
    esxcli system settings advanced list --option=/DataMover/HardwareAcceleratedMove
    # esxcli system settings advanced list --option=/DataMover/HardwareAcceleratedInit
Disabling VAAI when using NAS storage
When disabling NAS VAAI, there are no advanced configuration parameters that can be used. The plugin must be removed using below commands.

  1. Log into ESXi using SSH/DCUI and execute command:

    # esxcli software vib remove –-vibname=name

    For Example: # esxcli software vib remove –-vibname=NetAppNasPlugin

  2. Verify that the plugin has been removed using command:

    esxcli software vib list

  3. Reboot the ESXi host to take effect.



Note: Disabling the ATS (atomic test and set) parameter has the potential to cause data unavailability in ESXi 5.5 for volumes that were create as VMFS5 natively. Those volumes only support the use of ATS locking. Anything that is VMFS3 or upgrade from VMFS3 to VMFS5 should be fine. The other option would be to upgrade the ESXi host to version 6.x where we have added functionality to set the lock mode on native VMFS5 volumes that allows the old SCSI reservation method to function.

Additional Information

For more information, see the Turn off Hardware Acceleration section of the ESX Configuration Guide.

To revert this configuration and to enable vStorage APIs for Array Integration functionality, change each of these settings from 0 to 1.

For more information about locking mechanisms, see:
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See Also

This Article Replaces


Update History

08/30/2013 - Removed Note: You cannot disable or re-enable ATS-only on a VMFS-5 datastore which has been upgraded from VMFS-3. as it is incorrect. 01/13/2012 - Added ESXi 5.0 commands in the Disabling VAAI using an ESX/ESXi console connection section 07/25/2012 - Updated HardwareAcceleratedLocking PowerCLI command

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