Fight the FUD! – Not all VAAI-NAS storage solutions are created equal.

At a meeting recently, a potential customer who is comparing NAS/Hyper-converged solutions for an upcoming project advised me they only wanted to consider platforms with VAAI-NAS support.

As the customer was considering a wide range of workloads, including VDI and server the requirement for VAAI-NAS makes sense.

Then the customer advised us they are comparing 4 different Hyper-Converged platforms and a range of traditional NAS solutions. The customer eliminated two platforms due to no VAAI support at all (!) but then said Nutanix and one other vendor both had VAAI-NAS support so this was not a differentiator.

Having personally completed the VAAI-NAS certification for Nutanix, I was curious what other vendor had full VAAI-NAS support, as it was (and remains) my understanding Nutanix is the only Hyper-converged vendor who has passed the full suite of certification tests.

The customer advised who the other vendor was, so we checked the HCL together and sure enough, that vendor only supported a subset of VAAI-NAS capabilities even though the sales reps and marketing material all claim full VAAI-NAS support.

The customer was more than a little surprised that VAAI-NAS certification does not require all capabilities to be supported.

Any storage vendor wanting its customers to get support for VAAI-NAS with VMware is required to complete a certification process which includes a comprehensive set of tests. There are a total of 66 tests for VAAI-NAS vSphere 5.5 certification which are required to be completed to gain the full VAAI-NAS certification.

However as this customer learned, it is possible and indeed common for storage vendors not to pass all tests and gain certification for only a subset of VAAI-NAS capabilities.

The below shows the Nutanix listing on the VMware HCL for VAAI NAS highlighting the 4 VAAI-NAS features which can be certified and supported being:

1. Extended Stats
2. File Cloning
3. Native SS for LC
4. Space Reserve

This is an example of a fully certified solution supporting all VAAI-NAS features.

Here is an example of a VAAI-NAS certified solution which has only certified 1 of the 4 capabilities. (This is a Hyper-converged platform although they were not being considered by the customer)


Here is another example of a VAAI-NAS certified solution which has only certified 2 of the 4 capabilities. (This is a Hyper-converged platform).


So customers using the above storage solution cannot for example create Thick Provisioned Virtual Disks, therefore preventing the use of Fault Tolerance (FT) or virtualization of business critical applications such as Oracle RAC.

In this next example, the vendor has certified 3 out of 4 capabilities and is not certified for Native SS for LC. (This is a traditional centralized NAS platform).


So this solution does not support using storage level snapshots for the creation of Linked Clones, so things like Horizon View (VDI) or vCloud Director FAST Provisioning deployments will not get the cloning performance or optimal capacity saving benefits of fully certified/supported VAAI-NAS storage solutions.

The point of this article is simply to raise awareness that not all solutions advertising VAAI-NAS support are created equal and ALWAYS CHECK THE HCL! Don’t believe the friendly sales rep as they may be misleading you or flat out lying about VAAI-NAS capabilities / support.

When comparing traditional NAS or Hyper-converged solutions, ensure you check the VMware HCL and compare the various VAAI-NAS capabilities supported as some vendors have certified only a subset of the VAAI-NAS capabilities.

To properly compare solutions, use the VMware HCL Storage/SAN section and as per the below image select:

Product Release Version: All
Partner Name: All or the specific vendor you wish to compare
Features Category: VAAI-NAS
Storage Virtual Appliance Only: No for SAN/NAS , Yes for Hyperconverged or VSA solutions


Then click on the Model you wish to compare e.g.: NX-3000 Series


Then you should see something similar to the below:


Click the “View” link to show the VAAI-NAS capabilities and you will see the below which highlights the VAAI-NAS features supported.

Note: if the “View” link does not appear, the product is NOT supported for VAAI-NAS.


If the Features do not list Extended StatsFile CloningNative SS for LCSpace Reserve the solution does not support the full VAAI-NAS capabilities.

Related Articles:

1. My checkbox is bigger than your checkbox@HansDeLeenheer

2. Unchain My VM, And Set Me Free!(Snapshots)

3. VAAI-NAS – Some snapshot chains are deeper than others

How to configure Network I/O Control (NIOC) for Nutanix (or any IP Storage)

This video shows how to configure Network I/O Control (NIOC) as per Nutanix Best Practices, however this configuration is also applicable to any IP based Storage.

For more information see the Nutanix vNetworking Best Practices Guide.

Related Articles:

1. Network I/O Control Shares/Limits for ESXi Host using IP Storage

2. Network I/O Control for ESXi Host using IP Storage (4x10Gb NICs)

3. Example VMware vNetworking Design for IP Storage

Fight the FUD: vCenter on VDS on Nutanix NFS Datastore – Not a problem!

I saw this tweet (below) and was inspired to write this post as is appears there is still a clear misunderstanding of how the VMware Virtual Distributed Switch (VDS) functions when vCenter is down.


My interpretation was the tweet was suggesting/implying the following:

1. If vCenter (VC) is on a VDS there is a problem in the event of an outage

2. Having vCenter (VC) running on an NFS datastore is a problem

3. Nutanix environments have problems with VDS deployments

4. In the event of an outage where vCenter (VC) is on a VDS and the underlying storage is presented via NFS by Nutanix, that this is somehow worse than if the storage was presented by another storage vendor.

Long story short, none of the above are problems and the author of the tweet is simply mistaken.

I highly recommend watching this recording of a VMworld session by @chriswahl (VCDX#104) & @thejasonnash (VCDX#49) which covers Distributed Switches in depth.

NET2745 – vSphere Distributed Switch: Technical Deep Dive

Here is a Video showing how a Nutanix environment recovers with vCenter offline with everything including the Nutanix CVMs connected to a VDS.

In the video, the Nutanix controller VM is using a dvPortGroup with Ephemeral Binding, however Static Binding is also fully supported.

So we don’t need to imagine an outage, the above shows the process start to finish and its only a few minutes to be fully operational!



Related Articles:

1. Example Architectural Decision – Port Binding Setting for a dvPortGroup
2. Distributed vSwitches and vCenter outage, what’s the deal?@duncanyb (VCDX #007)