FSx for Windows File Server file systems should be configured for Multi-AZ deployment

How to fix it

• Replaces the resource: The deployment type is fixed at creation and a backup restores only to its own type, so create a Multi-AZ file system, copy the data with DataSync, repoint clients, then delete this one.
• Can break clients: Multi-AZ file systems do not support DFS Replication, so a Single-AZ 1 file system that relies on it needs another way to replicate.

In the console

Amazon FSx → Create file system → FSx for Windows File Server → Standard create

Deployment type

Multi-AZ

Preferred subnet

A subnet in the Availability Zone where most clients run

Standby subnet

A subnet in a different Availability Zone from the preferred subnet

Windows authentication

The Active Directory this file system is joined to, or one it trusts

With the AWS CLI

aws fsx create-file-system --file-system-type WINDOWS --storage-capacity <storage-gib> --subnet-ids <preferred-subnet-id> <standby-subnet-id> --windows-configuration ActiveDirectoryId=<directory-id>,DeploymentType=MULTI_AZ_1,PreferredSubnetId=<preferred-subnet-id>,ThroughputCapacity=<throughput-mbps> --region <region>

With Terraform

resource "aws_fsx_windows_file_system" "this" {
  deployment_type     = "MULTI_AZ_1"
  subnet_ids          = [var.preferred_subnet_id, var.standby_subnet_id]
  preferred_subnet_id = var.preferred_subnet_id
  active_directory_id = var.directory_id
  storage_capacity    = var.storage_capacity_gib
  throughput_capacity = var.throughput_capacity
}