# Inactive FSx File System | Cloud Efficiency Hub Canonical: https://www.pointfive.co/efficiency-hub/inefficiencies/inactive-fsx-file-system Amazon FSx file systems, whether FSx for Windows File Server, FSx for NetApp ONTAP, FSx for OpenZFS or FSx for Lustre, bill for the storage and... By: PointFive Updated: 2026-09-28 [Cloud Efficiency Hub](https://www.pointfive.co/efficiency-hub) The short version Amazon FSx file systems, whether FSx for Windows File Server, FSx for NetApp ONTAP, FSx for OpenZFS or FSx for Lustre, bill for the storage and throughput capacity configured on them, prorated by the hour, regardless of whether any client is reading or writing. PointFive Research Cloud cost research at PointFive AWS service [Amazon FSx](https://www.pointfive.co/efficiency-hub/cloud-services/amazon-fsx) Category [Storage](https://www.pointfive.co/efficiency-hub/service-category/storage) Reference CER-0401 Type Idle or Unused Resource ## Explanation Why the waste happens and who it affects. There is no stop or pause option, so a file system keeps its full cost until it is deleted. File systems are commonly left behind after a file server migration cutover, a finished HPC or analytics project, a proof of concept, or the retirement of the application that mounted them. Unlike Amazon EFS, which bills mainly for the data stored, an idle FSx file system with provisioned SSD storage and high throughput capacity can cost as much on a quiet day as on a busy one. Deleting it also needs care: FSx for Windows File Server takes a final backup by default when a file system is deleted, and that backup is not subject to the retention policy, so it keeps billing until someone deletes it manually. ## Billing model The pricing dimensions that drive this cost. Storage capacity Billed per GB-month of provisioned SSD or HDD capacity for most FSx deployment types, independent of activity Throughput capacity Billed per MBps-month of provisioned throughput whether or not clients generate traffic Provisioned SSD IOPS Billed per IOPS-month above the included baseline where user-provisioned IOPS are configured Backups Billed per GB-month; final and user-initiated backups persist after the file system is deleted ## How to detect 4 checks to find it in your estate. - For each file system, sum the CloudWatch metrics DataReadBytes, DataWriteBytes and MetadataOperations (AWS/FSx namespace, FileSystemId dimension) over 30 or more days and flag those at or near zero - Check ClientConnections where it is published (FSx for Lustre, and FSx for Windows file systems with at least 32 MBps throughput capacity) for sustained zero values - Cross-check the file system's DNS name, SVM endpoints or mount targets against application configuration, Active Directory group policies and EC2 fstab entries to confirm nothing still references it - Review tags, creation date and owner, and look for file systems tied to completed migrations, closed projects or deleted environments ## How to fix 5 ways to remove the waste. - Confirm with the owner that the data is no longer needed, or archive it to Amazon S3 or another lower-cost store before removal - Delete the file system with DeleteFileSystem; for ONTAP, delete its volumes and storage virtual machines first, and for Lustre, unmount it from all clients first - Decide explicitly on the final backup: skip it with SkipFinalBackup where it is not required, or record an expiry for it, since final and user-initiated backups continue to bill after deletion - If the file system is still needed occasionally, reduce throughput capacity to the lowest level that meets its needs, because storage capacity on most FSx types cannot be reduced in place - Tag FSx file systems with owner and expiry at creation and alert when client I/O stays at zero ## Documentation Vendor references for pricing and configuration. - [Amazon FSx for Windows File Server Pricing aws.amazon.com](https://aws.amazon.com/fsx/windows/pricing/) - [DeleteFileSystem - Amazon FSx API Reference docs.aws.amazon.com](https://docs.aws.amazon.com/fsx/latest/APIReference/API_DeleteFileSystem.html) - [Monitoring with Amazon CloudWatch - FSx for Windows File Server docs.aws.amazon.com](https://docs.aws.amazon.com/fsx/latest/WindowsGuide/fsx-windows-metrics.html) - [Amazon FSx for Lustre metrics and dimensions docs.aws.amazon.com](https://docs.aws.amazon.com/fsx/latest/LustreGuide/fs-metrics.html) - [COST04-BP01 Track resources over their lifetime docs.aws.amazon.com](https://docs.aws.amazon.com/wellarchitected/latest/cost-optimization-pillar/cost_decomissioning_resources_track.html) ## Related inefficiencies [Browse the library](https://www.pointfive.co/efficiency-hub) - Amazon FSx CER-0328 ### [Infrequently Accessed Data Retained on High-Performance FSx File Systems](https://www.pointfive.co/efficiency-hub/inefficiencies/infrequently-accessed-data-retained-on-high-performance-fsx-file-systems) Amazon FSx file systems are designed for performance-sensitive workloads such as shared enterprise file systems, high-performance computing, analytics, and machine learning. Storage costs are driven by provisioned capacity (measured in... Storage - Amazon FSx CER-0400 ### [Data Deduplication Disabled on FSx for Windows File Server](https://www.pointfive.co/efficiency-hub/inefficiencies/data-deduplication-disabled-on-fsx-for-windows-file-server) FSx for Windows File Server supports Microsoft Data Deduplication, which stores repeated chunks of data only once and compresses them, but it is not enabled by default. User home directories, departmental shares and software build shares... Storage - AWS S3 CER-0303 ### [Orphaned Cloud Storage from Dropped External Delta Tables in Databricks](https://www.pointfive.co/efficiency-hub/inefficiencies/orphaned-cloud-storage-from-dropped-external-delta-tables-in-databricks) When external Delta tables are dropped from Databricks Unity Catalog or the legacy Hive metastore, only the table metadata is removed - the underlying data files in cloud object storage (such as S3, ADLS, or GCS) remain untouched and... Storage --- Source: the public page above. Product screenshots and illustrative interfaces are examples, not live customer data.