VAAI Configuration

User Guides for VMware Solutions
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The VMware API for Array Integration (VAAI) primitives offer a way to offload and accelerate certain operations in a VMware environment.

Everpure requires that all VAAI features be enabled on every ESXi host that is using FlashArray storage. Disabling VAAI features can greatly reduce the efficiency and performance of FlashArray storage in ESXi environments.

All VAAI features are enabled by default (set to 1) in ESXi 5.x and later, so no action is typically required. Though these settings can be verified via the vSphere Web Client or CLI tools.

  1. WRITE SAME—DataMover.HardwareAcceleratedInit
  2. XCOPY—DataMover.HardwareAcceleratedMove
  3. ATOMIC TEST & SET— VMFSHardwareAcceleratedLocking

    Note:

    BEST PRACTICE: Keep VAAI enabled. DataMover.HardwareAcceleratedInit, DataMover.HardwareAcceleratedMove, and VMFS3.HardwareAcceleratedLocking

    In order to provide a more efficient heart-beating mechanism for datastores VMware introduced a new host-wide setting called /VMFS3/UseATSForHBOnVMFS5. In VMware’s own words:

    “A change in the VMFS heartbeat update method was introduced in ESXi 5.5 Update 2, to help optimize the VMFS heartbeat process. Whereas the legacy method involves plain SCSI reads and writes with the VMware ESXi kernel handling validation, the new method offloads the validation step to the storage system.“

    Everpure recommends keeping this value on whenever possible. That being said, it is a host wide setting, and it can possibly affect storage arrays from other vendors negatively.

    Read the VMware KB article here:

    ESXi host loses connectivity to a VMFS3 and VMFS5 datastore

    Everpure is NOT susceptible to this issue, but in the case of the presence of an affected array from another vendor, it might be necessary to turn this off. In this case, Everpure supports disabling this value and reverting to traditional heart-beating mechanisms.

    Note:

    BEST PRACTICE: Keep VMFS3.UseATSForHBOnVMFS5 enabled—this is preferred. If another vendor is present and prefers it to be disabled, it is supported by Everpure to disable it.

    For additional information please refer to Web Guide: VMware Storage APIs for Array Integration with the Everpure® FlashArray document.