How to enable VAAI on ESX for XIV storage

Many administrators don’t know how powerful VAAI (storage hardware acceleration)  is, some of them ignores but if your storage supports VAAI I strongly recommend to enable it in your environment, you will see how beneficial it is and you will love it, I guarantee 🙂 . You can see benefits on one of my latest posts:

[box type=”info”][/box]

How to enable VAAI on your ESX(i) ? Is enabled by default on ESX(i) hosts but to have it supported you must enable it on storage . Below example shows how to enable VAAI support on IBM XIV storage.


  • vSphere 4 as a hypervisor
  • XIV microcode 10.2.4a

VAAI not supported

What to do ?

  1. Make sure that you have the latest microcode on IBM XIV installed – if not update it
  2. Download IBM XIV driver for ESX(i) hypervisor
    [box type=”download”] Download XIV driver for vSphere[/box]
  3. Install driver:
    • on ESX
      [sourcecode language=”bash”]
      esxupdate – –nodeps –maintenancemode update
    • on ESXi
  4. Reboot server
  5. If you have ESX installed you have to claim XIV LUNs manually ( ESXi can claim LUNs automatically and manual intervention is not needed).
  6. Verify whether LUNs were claimed by driver or not, execute below command from ESX console and check name for VAAI Plugin name; should be IBM_VAAIP_MODULE
  7. Increase data transfer chunk size from default 4096kB to 16384kB
    [sourcecode language=”bash”]esxcfg-advcfg /DataMover/MaxHWTransferSize -s 16384 [/sourcecode]
  8. Done, now in column Hardware acceleration, status is supported

VAAI support enabled

[box type=”info”] IBM guide for VAAI configuration on ESX and XIV[/box]

Artur Krzywdzinski

Artur is Consulting Architect at Nutanix. He has been using, designing and deploying VMware based solutions since 2005 and Microsoft since 2012. He specialize in designing and implementing private and hybrid cloud solution based on VMware and Microsoft software stacks, datacenter migrations and transformation, disaster avoidance. Artur holds VMware Certified Design Expert certification (VCDX #077).