The Continuous Availability feature for Azure NetApp Files SMB volumes is specifically designed to support non-disruptive operations for business-critical workloads like FSLogix profile containers. It leverages SMB Transparent Failover, which allows the Azure NetApp Files service to perform planned maintenance and service updates by transparently moving active SMB sessions to another healthy storage endpoint. This ensures that user sessions in the Azure Virtual Desktop environment remain connected and operational without any interruption, which is the core requirement of the question.

A. Configure Cross-Zone Replication: This is a disaster recovery (DR) feature for data protection across availability zones. A failover is a manual and disruptive process, not a non-disruptive maintenance operation.

C. Enable Volume Placement: This feature controls the deployment of a volume into a specific availability zone for high availability architecture, but it does not prevent service interruptions during backend maintenance.

D. Enable Azure NetApp Files Snapshot: Snapshots provide point-in-time data protection for backup and recovery purposes. They do not ensure continuous access to data during service maintenance events.

1. Microsoft Learn, "Benefits of using Azure NetApp Files": Under the "Continuous availability" section, it states, "The SMB Continuous Availability feature enables non-disruptive maintenance operations on the Azure NetApp Files service... Azure NetApp Files supports SMB Transparent Failover on SMB volumes... This feature is a critical component for the SQL Server and FSLogix Profile Container workloads."

2. Microsoft Learn, "Use SMB Continuous Availability with Azure NetApp Files...": This document explicitly details the use case: "By using Azure NetApp Files with SMB continuous availability, you can improve the resiliency of FSLogix Profile Container... SMB Transparent Failover enables maintenance operations on the Azure NetApp Files service without interrupting connectivity to server applications storing and accessing data on SMB volumes."

3. Microsoft Learn, "Create an SMB volume for Azure NetApp Files": In the steps for creating an SMB volume, the documentation for the "Enable Continuous Availability" option states, "This feature allows for SMB Transparent Failover to enable non-disruptive maintenance operations and improves SMB resiliency to network failures."