Where Does FSx Need to Reside?

FSx is always deployed inside an Amazon VPC

Amazon FSx—whether FSx for Windows File Server, FSx for Lustre, FSx for NetApp ONTAP, or FSx for OpenZFS—is a VPC-scoped service.
It cannot be deployed outside a VPC.

✅ Does FSx Need Subnets? Yes. And the Requirements Differ by Type

1. FSx for Windows File Server

  • ✅ Requires two subnets in the same VPC (for Multi-AZ deployments).

  • ✅ Subnets must be in different Availability Zones.

  • ✅ Uses ENIs inside these subnets.

  • ✅ Must be placed in private subnets (recommended for AD connectivity).

Why 2 subnets?
To support Multi-AZ HA with automatic failover.

Examples of Availability Zone (AZ) names within a single AWS region:

  • us-east-1a

  • us-east-1b

Both belong to the us-east-1 (N. Virginia) region.