# Inactive DMS replication instance | Cloud Efficiency Hub

Canonical: https://www.pointfive.co/efficiency-hub/inefficiencies/inactive-dms-replication-instance

Replication instances are commonly left running after migration tasks are completed, especially when DMS is used for one-time or project-based migrations.

By: Tom Cross

Updated: 2026-09-28

[Cloud Efficiency Hub](https://www.pointfive.co/efficiency-hub) 

# Inactive DMS Replication Instance

The short version

Replication instances are commonly left running after migration tasks are completed, especially when DMS is used for one-time or project-based migrations.

[Tom Cross](https://www.linkedin.com/in/tomcross/)

FinOps Lead @ Aer Lingus

AWS service

[AWS DMS](https://www.pointfive.co/efficiency-hub/cloud-services/aws-dms)

Category

[Databases](https://www.pointfive.co/efficiency-hub/service-category/databases)

Reference

CER-0140

Type

Idle or Unused Resource

## Explanation

Why the waste happens and who it affects.

Without active replication tasks, these instances no longer serve any purpose but continue to incur hourly compute costs. In large organizations or decentralized migration projects, these idle instances may go unnoticed, contributing to persistent background spend.

## Billing model

The pricing dimensions that drive this cost.

- DMS Replication Instances are charged per hour of uptime, based on instance size

- Charges accrue even if no replication tasks are actively running

- Additional storage charges may apply for logs and cached data, but the bulk of cost comes from the instance itself

## How to detect

4 checks to find it in your estate.

- List all DMS replication instances in the account or region

- Check whether each instance has active replication tasks associated with it

- Flag instances with zero tasks or tasks in a stopped or completed state

- Review instance creation and last activity timestamps to identify long-idle resources

## How to fix

4 ways to remove the waste.

- Delete DMS replication instances that are no longer associated with active or planned tasks, after stopping and deleting their tasks; replication instances cannot be stopped, so deletion is the only way to end instance charges

- Tag replication instances by project or migration wave to enable future clean-up

- Incorporate DMS instance lifecycle checks into post-migration workflows

- Use infrastructure-as-code where possible to ensure temporary resources are cleaned up automatically

## Documentation

Vendor references for pricing and configuration.

- [AWS DMS Pricing  aws.amazon.com](https://aws.amazon.com/dms/pricing/)

- [Monitoring AWS DMS tasks  docs.aws.amazon.com](https://docs.aws.amazon.com/dms/latest/userguide/CHAP_Monitoring.html)

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[Browse the library](https://www.pointfive.co/efficiency-hub)

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