FSx — Concept
What it is
Amazon FSx = fully managed third-party file systems, exposed as native services. Four flavors, each for a specific workload.
| Flavor | Protocol | Use |
|---|---|---|
| FSx for Windows File Server | SMB (CIFS) | Windows workloads, Active Directory integration |
| FSx for Lustre | POSIX (Lustre client) | HPC, ML training, financial modeling, video render |
| FSx for NetApp ONTAP | NFS + SMB + iSCSI | Existing NetApp customers, multi-protocol, snapshots, dedupe |
| FSx for OpenZFS | NFS | High-performance ZFS features (snapshots, cloning) on Linux |
Why each exists
- Windows: EFS doesn't speak SMB; many enterprise apps require Windows file shares with AD ACLs.
- Lustre: parallel file system that delivers hundreds of GB/s, integrates with S3 as the durable backing store.
- ONTAP: lift-and-shift NetApp workloads; multi-protocol shares.
- OpenZFS: cheap, high-perf NFS with snapshots and clones.
How it works (common)
- Each FSx file system lives in a VPC.
- Mounted by EC2 (and sometimes on-prem via VPN/DX) using the appropriate protocol.
- Backups to S3 (managed), encryption at rest with KMS.
- Multi-AZ supported on Windows / ONTAP (Lustre & OpenZFS are typically single-AZ).
FSx for Lustre specifics (popular on exam)
- Can be linked to an S3 bucket: S3 objects appear as files; results can be written back to S3.
- Two deployment types:
- Scratch — single-AZ, fastest, not durable, for temporary jobs.
- Persistent — durable, replicated within AZ, longer-term HPC clusters.
- Throughput: up to 1 TB/s aggregate.
When to use vs alternatives
| Need | Use |
|---|---|
| Windows SMB shares | FSx for Windows |
| Linux NFS for app servers | EFS (or FSx OpenZFS) |
| ML / HPC parallel scratch | FSx for Lustre (Scratch) |
| HPC with durability | FSx for Lustre (Persistent) |
| Multi-protocol legacy NetApp | FSx for ONTAP |
| Object storage, no FS mount | S3 |
Common exam scenarios
- "Windows app on EC2 needs shared file storage with AD ACLs" → FSx for Windows (joined to Microsoft AD or AD Connector).
- "ML training reads 100 TB from S3 at extreme throughput" → FSx for Lustre linked to the S3 bucket.
- "Migrate existing NetApp workload as-is to AWS" → FSx for ONTAP.
- "Linux NFS share, lots of small files, snapshots & clones" → FSx for OpenZFS.
- "Cheap general Linux NFS" → EFS (not FSx).
Exam tip
Windows in the question → FSx for Windows. HPC / ML / parallel → FSx for Lustre. Linux NFS, simple, multi-AZ → EFS is usually the right answer.