Clarity on vTPM Support for Nutanix AHV VMs with VBAHV 7 (VBR 12.3)

[K-taira]

Hello everyone!

We are seeking clarification on the support status for vTPM-enabled VMs on Nutanix AHV with Veeam Backup for Nutanix AHV 7 (and VBR 12.3). We are planning to deploy Windows Server 2025 VMs with vTPM enabled and need to confirm if they can be reliably backed up and restored.
Our investigation into the official documentation has led to some seemingly conflicting information, and we would appreciate your help in clarifying the official support stance.

[ Environment ]
- Veeam Backup & Replication Version: 12.3
- Veeam Backup for Nutanix AHV: 7
- Hypervisor: Nutanix AHV
- Target VM: Windows Server 2025 (with vTPM enabled)
- Nutanix AOS Version: 6.10.1.6
- Prism Central Version: pc.2024.2.0.13

[ Summary of Our Findings and Contradictions ]
Our investigation into Veeam and Nutanix documentation has led to some confusion regarding the supportability.

A. "Fully Supported" mentioned in Veeam B&R v13's "What's New":
This document states that full support for vTPM was introduced in v13, which implies that previous versions like v12.3 did not have full support.

vTPM support - VMs with virtual Trusted Platform Modules are now fully supported for backup and restore.
(Source: https://www.veeam.com/veeam_backup_13_whats_new__wn.pdf)

B. Limitation Mentioned in the VBAHV 7 User Guide:
The user guide for VBAHV 7 (Archived) states a limitation for Windows 11 VMs on AOS 6.6.

You cannot back up Windows 11 VMs due to AOS 6.6 technical limitations related to Virtual Trusted Platform Module (vTPM) support.
(Source: https://helpcenter.veeam.com/archive/vb ... sites.html)

C. System Requirements for VBAHV 7:
The same user guide states that the supported AOS versions are 6.8.1.6 to 7.3.1.1.
This suggests the limitation mentioned in point (B) for AOS 6.6 is not relevant for officially supported configurations.

Veeam Backup for Nutanix AHV is compatible with Nutanix AOS versions 6.8.1.6-7.3.1.1...
(Source: https://helpcenter.veeam.com/archive/vb ... ments.html)

D. Nutanix KB Article:
A Nutanix KB article clarifies that they started supporting third-party backups for vTPM-enabled VMs from AOS 6.8 onwards, and advises checking with the backup vendor for their support status.

Versions affected: AOS 6.7.x, AOS 6.6.x, AOS 6.5.x, ALL AHV Versions
Solution: Starting with AOS 6.8, Nutanix supports protecting vTPM-enabled VMs using third-party backups. Reach out to your backup vendor to ensure they support backing up vTPM-enabled VMs as well.
(Source: https://portal.nutanix.com/page/documen ... 000H4a0SAC)

While points (C) and (D) lead us to believe that VBAHV 7 should support vTPM-enabled VMs on a supported AOS version (like our 6.10.1.6), this seems to conflict with the statement in point (A) that "full support" was a new feature in v13.
This discrepancy makes it difficult for us to determine the correct course of action.

[ Our Specific Questions ]
Based on the information above, could you please clarify the following points?

1. Does VBAHV 7 (with VBR 12.3) fully support the backup and restore of vTPM-enabled VMs (such as Windows Server 2025) on supported Nutanix AOS versions (6.8.1.6 - 7.3.1.1)?

2. If the answer to question #1 is "not fully supported, but partially supported," what are the specific limitations or unsupported features and conditions we should be aware of?

3. If it is supported (either fully or partially), are there any special configurations required on the Veeam side to perform backups and restores of vTPM-enabled VMs?

4. If it is not supported at all in this version, is our understanding correct that upgrading to Veeam B&R v13 and VBAHV 9 would provide the full support required?

We would greatly appreciate your expert insight to resolve this ambiguity.

Thank you for your time and assistance.