Azure NetApp Files (ANF) is a first-party, fully managed Azure service that is certified by both Microsoft and VMware as a supplemental datastore for Azure VMware Solution (AVS). It directly addresses the scenario's requirements by allowing storage to be scaled independently of compute. For workloads requiring more storage than compute, ANF is highly cost-effective because it avoids the need to purchase additional AVS nodes (which include both compute and storage) just to meet storage capacity demands. Its high-performance, low-latency characteristics are ideal for demanding VMware environments.

B. Azure Files: While it offers NFS shares, it is not certified or optimized as a primary, high-performance datastore for enterprise VMware workloads within AVS, unlike Azure NetApp Files.

C. Amazon FSx for NetApp ONTAP: This is an AWS (Amazon Web Services) offering and is not applicable to a solution being deployed within the Microsoft Azure cloud.

D. Cloud Volumes ONTAP in Azure: This is a customer-managed IaaS solution. While viable, Azure NetApp Files is a fully managed PaaS offering, providing a more integrated and simpler solution with less management overhead for this specific use case.

1. Microsoft Azure Documentation: "Attach Azure NetApp Files datastores to Azure VMware Solution hosts". This document explicitly states, "Azure NetApp Files provides a scalable and high-performance storage solution... It lets you scale storage independently of compute, going beyond the limits of the local instance storage provided by vSAN. You can create datastores on Azure NetApp Files NFS volumes and attach them to clusters of your choice." (Section: "Introduction")

2. NetApp Technical Report TR-4871: "Azure NetApp Files with Azure VMware Solution". The introduction states, "Azure NetApp Files datastores for Azure VMware Solution (AVS) provide a way for you to expand your storage capacity beyond the storage provided by vSAN on AVS hosts... This capability allows you to scale storage and compute independently." (Page 4, "Introduction")

3. VMware Docs: "Using Azure NetApp Files with Azure VMware Solution". This official VMware documentation confirms the partnership and use case: "Azure NetApp Files is an Azure native, first-party service for migrating and running the most demanding enterprise file-workloads in the cloud... Azure NetApp Files is certified for use as a datastore for Azure VMware Solution." (Section: "Key Features")