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Metro Availability with Witness VM for AHV clusters – supported?

  • February 3, 2026
  • 6 replies
  • 27 views
Daniel Martinez
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Hello,

I’m reviewing the official Nutanix documentation regarding Metro Availability with Witness VM, and I have a question I’d like to clarify.

We are planning a Metro Availability (synchronous replication) setup between two Nutanix AHV clusters, and we would like to deploy a Witness VM in a third site to provide quorum and avoid split-brain scenarios.

From what I have seen so far in the official Nutanix documentation, most references to Metro Availability with a Witness VM seem to be focused on VMware HA (ESXi) environments, and I have not found a clear and explicit confirmation regarding AHV-to-AHV Metro Availability using a Witness VM.

Could someone please confirm:

  • Whether Metro Availability between two AHV clusters using a Witness VM in a third site is officially supported

  • And if there is any official documentation or KB that explicitly covers this scenario for AHV

I just want to make sure the design is fully supported before moving forward.

Thanks in advance for the clarifications!

Best answer by JeroenTielen

YEs. So for Metro AHV do have automatic failover you need a Witness VM on a third location. That is correct. 

 

But the witness VM is optional. If you want to do the failover manual then you dont need the witness vm. 

6 replies

Daniel Martinez
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While searching more info I’ve found this link...

https://portal.nutanix.com/page/documents/details?targetId=Disaster-Recovery-DRaaS-Guide-vpc_7_5:ecd-ecdr-independentwitness-metro-pc-c.html

I assume it confirms that you can use a Witness VM to provide the witness service on a third site for AHV clusters (metro-availablity)

K
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  • Khoskin
  • Trendsetter
  • February 3, 2026

its a bit unclear.  I have only worked with metro in a ESX scenario.  We had two clusters registered with one PC in two different sites, the witness VM sat on a esx host on a third site.  The doc you have listed seems to mention using the witness service on the PC where the AHV clusters are registered.  A bit confusing as to what it means!

You can also configure Witness Service in the following environments:

Inside the Prism Central Instance:
To monitor Metro Availability health between AHV clusters registered to the same Prism Central instance, you can configure Witness Service within the Prism Central instance. For more information, see Witness Service Hosted Inside the Prism Central Instance.
On ESXi clusters running protection domains:
To monitor Metro Availability between ESXi clusters, you can configure Witness VM in a separate fault domain.

 

Daniel Martinez
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its a bit unclear.  I have only worked with metro in a ESX scenario.  We had two clusters registered with one PC in two different sites, the witness VM sat on a esx host on a third site.  The doc you have listed seems to mention using the witness service on the PC where the AHV clusters are registered.  A bit confusing as to what it means!

You can also configure Witness Service in the following environments:

Inside the Prism Central Instance:
To monitor Metro Availability health between AHV clusters registered to the same Prism Central instance, you can configure Witness Service within the Prism Central instance. For more information, see Witness Service Hosted Inside the Prism Central Instance.
On ESXi clusters running protection domains:
To monitor Metro Availability between ESXi clusters, you can configure Witness VM in a separate fault domain.

 

Yeah, documentation is a bit confusing. Here are other interesting link:

Nutanix Disaster Recovery pc.7.5 - Requirements and Recommendations for Witness Service Hosted Outside the Prism Central Instance

There you can read these:
 

Ensure that you meet the following requirements and recommendations before configuring Witness Service hosted outside the Prism Central instance:

These requirements are in addition to the Requirements for Synchronous Replication and the applicable Requirements for DR Configuration between On-Prem AZs.

  • The primary and recovery AHV clusters must be registered to a Prism Central instance.

    Witness Service supports Metro Availability between the clusters registered to the same or different Prism Central instances.

  • The primary and recovery AHV clusters registered to the Prism Central instances must run a supported AOS version.

    For Prism Central and AOS version compatibility, see Compatibility and Interoperability Matrix.

  • The Prism Central instances must run pc.2024.3 or later to be able to use Witness Service.
  • The AHV cluster hosting the Witness Service VM (WSVM) must run AOS version 7.0 or later

 

 

So based on the previous info, I understand that you can deploy AHV clusters, link them to different Prism Centrals and later create a metro-availability between them with a Witness Service (VM) on a third site…. Is that corret??

 

JeroenTielen
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  • JeroenTielen
  • Vanguard
  • Answer
  • February 3, 2026

YEs. So for Metro AHV do have automatic failover you need a Witness VM on a third location. That is correct. 

 

But the witness VM is optional. If you want to do the failover manual then you dont need the witness vm. 

Nutanix NTC 2022+2023+2024+2025+2026 || Nutanix NUG Champion || Nutanix Certified Instructor
    K
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    • Khoskin
    • Trendsetter
    • February 3, 2026

    so there is a witness VM (AHV) you can download PD-Based DR 7.0 - Installing a Witness VM  trouble is you’ll need a bit of tin running Nutanix to spin it up on.  Back in the day (before Broadcom decided to fleece us all) we just had an old server running ESX just for hosting the witness so it was minimal cost as you can put esx on just about anything.

    Daniel Martinez
    Forum|alt.badge.img+1

    so there is a witness VM (AHV) you can download PD-Based DR 7.0 - Installing a Witness VM  trouble is you’ll need a bit of tin running Nutanix to spin it up on.  Back in the day (before Broadcom decided to fleece us all) we just had an old server running ESX just for hosting the witness so it was minimal cost as you can put esx on just about anything.

    Thats one of the options for the customer, but he initialy prefers to have the witness on a clustered cloud site. He has AWS with EC2 which seems to be not working for this purpose cause the Foundation VM is provided in QCOW or OVA and none of them is supported on AWS EC2. So we will try to provide the hosting of the witness VM on our AHV cloud host enviroment.

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