vSphere 6.x: VMXNET3 and DirectPath I/O issue

vSphere 6.0 and 6.5 have an interesting bug in the vSphere Web Client: a DirectPath I/O option is enabled by default for a new virtual machine with VMXNET3 network adapter provisioned.

A New Virtual Machine dialogue looks good.

vm-provisioning

However, when I open the VM settings, surprise surprise, it is quite different.

vm-settings

I have done my research and found the DirectPath I/O option was enabled regardless the VM hardware version (checked all versions starting from 8 to 13). VMware explains this behaviour in a KB # 2145889 with the recommendation to disable this parameter.

My next thought was to find all VMs that had the same problem. Thanks to VMware and its vast community, I was able to find some useful examples (here, here, and here) for a PowerCLI script below.

Feel free to use this code.

28/11/2016 – Update 1: vSphere Client (C#) and vSphere HTML5 Web Client (Fling) also create VMs with the DirectPath I/O option enabled.

28/11/2016 – Update 2: The workaround is to use PowerCLI to provision a new VM.

26/04/2017 – Update 3: The solution to this problem has been provided by LucD. I am working on an updated script which automate the process of disabling DirectPath I/O for the VMs.

5 thoughts on “vSphere 6.x: VMXNET3 and DirectPath I/O issue

  1. Hi, any idea how I could possibly check this out on HW v10? For some reason creating a new VM from powercli is enabling DirectPath I/O on the network card and I can’t seem to get it disabled (The template is disabled) and can’t find .ExtensionData.UptCompatibilityEnabled. Any help is appreciated!

    Liked by 1 person

    • Hi simnether,

      Thank you for your question.

      I have updated my script to show information about the DirectPath I/O status regardless the VM hardware version.

      Like

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