vSphere 6 – Hardware Version 11

There are a some lesser known things that are enabled as part of vSphere 6’s VM hardware version 11 that I haven’t seen many people talking about, so I thought I would share some details.

USB 3.0

Introduced with vSphere 6 in VM hardware version 11 (HW11) is a new USB controller that is properly compatible with USB 3.0. I say “properly” because vSphere 5.5 did have the xHCI virtual controller but it wasn’t enabled by default (and therefore not supported). With vSphere 6, the included xHCI controller has been updated from v0.96 to v1.0 and is available for use with VMs that are at HW11.

By default, HW11 VMs are configured with the new xHCI controller. You still have the ability to add legacy USB controllers to virtual machines, and they can happily co-exist with the new xHCI controller too, but since the new controller is backwards compatible with USB 2.0 I don’t see much of a use case for this. The vSphere 6 xHCI controller supports up to 8 devices or “ports”. Four are reserved for USB 3.0 and four are reserved for USB 2.0 and you can add multiple USB controllers concurrently if you require more USB ports. The vSphere 6 Configuration Maximums does advise the following:

“USB 1.x, 2.x and 3.x supported. One USB host controller of each version 1.x, 2.x, or 3.x can be added at the same time.”

VMXNET3 LRO

The VMXNET3 driver for Windows based OSs (Win8/2012 and later) now supports Large Receive Offload (LRO). This is a special hardware technique that reduces the work of processing a number of smaller incoming network packets by combining them into a larger single packet. Microsoft calls this Receive Segment Coalescing (RSC), but the technology is the same. RSC is enabled by default within Windows, but you can change the setting with some simple PowerShell commands:

Set-NetOffloadGlobalSetting –ReceiveSegmentCoalescing Disabled
Set-NetOffloadGlobalSetting –ReceiveSegmentCoalescing Enabled

You need to keep this in mind when building your new Windows VMs. LRO / RSC can have a small impact to applications if they require or depend on network traffic to hit the VM in a constant stream of small packets. An example of this might be a trading platform where milli and micro-seconds count.

VMCI Firewall

The VMCI (Virtual Machine Communication Interface) allows VMs to communicate with each other or the host, but without needing to traverse the network. If you’ve seen VMware shared folders on VMware Fusion or Workstation, then you’ve seen this in action. NSX also uses VMCI to update the configuration of control VMs and Edge devices. Why would anyone want to use this? Well, if you want to get data in or out of a VM without needing to traverse a network stack, VMCI can achieve nearly 10Gbps!

When using VMCI (which is not enabled by default) you may notice that there is a virtual hardware device labeled “VMCI device” within the VM’s hardware settings. When using HW11 there’s a new “filter” option within this device, this allows you to create firewall rules on a per VM basis. By default, VMCI allows all traffic but you can add rules to restrict how you want VMCI traffic to flow. The VM’s .vmx configuration file will hold not only the VMCI PCI device information, but also the filter configuration. This allows the configuration to move around with the VM as it moves from host to host. You can add, delete, edit and re-sort the order of the VMCI rules and they are applied top down.

4 thoughts on “vSphere 6 – Hardware Version 11”

  1. I’d like to use your book in a vSphere 6 VCP-DCV college class, where my students build their own lab from the ground up (yes we have 16 GB of RAM and i7 processors). Could you recommend or provide a lab topology that would work well with your book? Also, a suggestion for future books is to include specific numbered exercises (like Lab 1: Installing ESXi interactively, Lab 2: …) so that these could be assigned and graded as students build, configure, and troubleshoot their own private cloud using a virtualized environment. Thanks for a great resource!

      1. Thanks for your reply, Nick. I am already aware of the publisher materials. However, there is no recommended lab setup, or even better, OVA files to use in setting up a lab. The only thing that the publisher provides are a sample syllabus, a few exam questions, a few exercises that are not hands-on (just questions), and some PowerPoint slides that leave a lot to be desired (as is the case with most publishers). What I am looking for is a set of lab exercises that starts with creating VMs in VMware Workstation such as a domain controller with DNS services, ESXi hosts, perhaps an iSCSI SAN, and vCenter Server set up in a lab topology that can be used to perform all the competencies in the book, such as FT, HA, DRS, host profiles, templates, networking, and so forth. This would end up being a complete virtual lab tailored to performing all the exercises in the book. This can be done using nested virtualization. The difficulty I find in using your book and many others in the classroom (or for an individual prepping for a cert on their own) is that there isn’t a defined set of Lab Exercises (such as Lab 01: Creating a Domain Controller with DNS Services | Lab 02: Installing ESXi into a VM | Lab 03: Setting up vCenter Server Appliance | Lab 04: Configuring Networking, and so forth). These exercises scattered in a series throughout the book would guide the student in setting up their own lab environment and learning the skills. By numbering the labs, it would be easy to assign and grade the assignments and would guide the student in learning hands-on skills. To me, this is just good common sense in putting together training materials. There’s a lot of IT workers that would benefit greatly with this sort of approach – IT people that do not know VMware very well and do not have access to a VMware environment but want to learn it. I see this every day as about half of my students already work in IT. Last time I offered this class, we used VCP5-DCV Study Guide by Brian Atkinson and published by Sybex (ISDN: 978-1-118-65844-4). It includes such exercises. However, the book assumes you already have a vSphere environment to work in. Most students don’t, so I had to supplement the exercises in the beginning to have students set up their own lab environment using VMs. It would be somewhat easy and very valuable to adapt your next edition by adding such exercises and guiding readers through creating their own lab environment. It could be a great supplement to add to your current book, and I would be glad to help in putting it all together. I’ll have to anyway for my upcoming fall class on VCP-DCV. By the way, I am the Department Chair and faculty at a public community college where we not only teach VMware skills, but are also a Cisco Networking Academy, CompTIA Partner, EC-Council Authorized Training Center, and a Red Hat Academy in addition to being a VMware IT Academy.

Leave a Reply

Your email address will not be published. Required fields are marked *