FSx for Windows / Lustre / NetApp / OpenZFS

EFS only speaks NFS to Linux. Many real workloads need something specific: Windows apps expect SMB and Active Directory; HPC and ML training need a parallel filesystem wired to S3; teams migrating off on-prem NetApp want ONTAP features like snapshots and dedup unchanged. Amazon FSx runs four battle-tested filesystems as a managed service — you get the exact protocol and feature set your software was built for, without running the file servers yourself.

• An FSx file system is deployed into a VPC and can be Single-AZ (lower cost, one AZ blast radius) or Multi-AZ (a standby in a second AZ with automatic failover). Multi-AZ availability varies by flavour — Windows and ONTAP support it natively; Lustre is Single-AZ (with S3 as the durable copy).
• Backups go to S3 (Regional). ONTAP and OpenZFS also support cross-Region replication.
• Clients connect over the VPC via a DNS name; on-prem access is possible over Direct Connect or VPN.

graph TD
FSX(("Amazon FSx"))
FSX --> WIN["FSx for Windows File Server"]
FSX --> LUS["FSx for Lustre"]
FSX --> ONT["FSx for NetApp ONTAP"]
FSX --> ZFS["FSx for OpenZFS"]
WIN -->|"SMB + Active Directory, NTFS ACLs"| WINU(("Windows apps, .NET, SQL Server"))
LUS -->|"POSIX, linked to an S3 bucket"| LUSU(("HPC, ML training, media rendering"))
ONT -->|"NFS + SMB + iSCSI, snapshots, dedup"| ONTU(("NetApp migrations, multi-protocol"))
ZFS -->|"NFS, ZFS snapshots & clones"| ZFSU(("Linux workloads wanting ZFS features"))
classDef win fill:#e8f0fe,stroke:#3b82f6,stroke-width:2px,color:#173a70
classDef lus fill:#eaf7ec,stroke:#2e8b3d,stroke-width:2px,color:#1a3d20
classDef ont fill:#f3ecfb,stroke:#8b3de0,stroke-width:2px,color:#3a1a5c
classDef zfs fill:#fdf0e6,stroke:#e0842e,stroke-width:2px,color:#6b3b0f
class WIN win
class LUS lus
class ONT ont
class ZFS zfs

Flavour	Protocol	Reach for it when
Windows File Server	SMB, integrates with AD / Managed Microsoft AD	Windows/.NET apps, home directories, SQL Server file shares, lift-and-shift of Windows workloads
Lustre	POSIX, high-throughput parallel FS	HPC, ML training, genomics, video processing — especially with a linked S3 bucket it lazy-loads and writes back to
NetApp ONTAP	NFS, SMB, and iSCSI simultaneously	Migrating from on-prem NetApp; need snapshots, cloning, compression/dedup, or multi-protocol access to the same data
OpenZFS	NFS (v3/v4)	Linux workloads that want ZFS snapshots, instant point-in-time clones, and sub-millisecond latency without ONTAP licensing

You pay for provisioned storage capacity per GB-month, provisioned throughput / SSD IOPS, and backups (per GB in S3). Multi-AZ roughly doubles the storage cost of Single-AZ. Lustre offers cheaper HDD and scratch options for transient jobs. Unlike EFS, FSx capacity is provisioned — you can grow it, but not shrink it — so right-size at creation.

• “Windows” + “file share” + “Active Directory” → FSx for Windows File Server, every time. EFS is Linux/NFS only.
• “HPC”, “machine learning training”, “millions of IOPS”, “hundreds of GB/s”, “process data in S3” → FSx for Lustre. It can present an S3 bucket as a filesystem and sync changes back.
• “Migrating from NetApp / on-prem NAS”, “need NFS and SMB access to the same data”, “dedup/compression/snapshots” → FSx for NetApp ONTAP.
• “Move a ZFS/Linux file server to AWS with minimal changes”, “point-in-time clones” → FSx for OpenZFS.
• Lustre file systems come in Scratch (temporary, no replication — cheapest, for short jobs) and Persistent (replicated within one AZ, for longer-lived data) deployment types.