Azure Database Migration Service: Target PostgreSQL Database Disappeared After Cancelling Online Migration

Question

Hi Team,

We encountered an unexpected issue while migrating an AWS RDS PostgreSQL database to Azure Database for PostgreSQL Flexible Server using the Azure Database Migration Service (Integrated Migration Experience).

Environment

• Source: AWS RDS PostgreSQL
• Target: Azure Database for PostgreSQL Flexible Server
• Migration Type: Online Migration
• Database Name: mirthdb
• Database Size: Approximately 171 GB

Issue

The online migration was running successfully and eventually reached the "Action Pending / Waiting for User Action" state.

At that point, we clicked Cancel Migration from the Azure Portal because we wanted to stop the migration.

After the cancellation completed, we found that the target database (mirthdb) no longer existed on the Azure PostgreSQL Flexible Server.

Investigation

We checked the Azure Activity Log for the PostgreSQL Flexible Server.

The only events recorded are:

• Update a database migration workflow (Started)
• Update a database migration workflow (Succeeded)

There are no delete operations recorded for the database or the PostgreSQL server.

Questions

1. Is it expected behavior for Azure Database Migration Service to delete the target database when an online migration is cancelled?
2. Does Azure Database Migration Service perform any internal cleanup that removes the target database?
3. If so, where is this behavior documented?
4. If not, how can we determine what deleted the target database?
5. Are there any backend logs or diagnostic logs that can help identify whether Azure DMS executed a DROP DATABASE operation?
6. Has anyone experienced similar behavior during an online PostgreSQL migration?

We would appreciate any guidance from the Microsoft team or anyone who has encountered this scenario.

Thank you.

Answer 1

hi Prajapati, Chirag & thx for sharing urs issue here at Q&A portal,

This is not something I’d treat as normal without product-team confirmation. The Activity Log only shows the migration workflow updates because a database-level DROP DATABASE issued through the PostgreSQL engine would not appear as an ARM delete event. So the absence of a delete operation in Azure Activity Log doesn’t prove the database wasn’t removed by the migration service. The key question is whether cancelling an online migration while it is in Action Pending / Waiting for User Action triggers cleanup of the target database created for that migration. I’m not aware of clear public documentation that says cancellation will delete the target database, so Microsoft should confirm whether this is expected behavior or a bug.

Check PostgreSQL server logs and auditing, if they were enabled at the time. A server log entry may show a DROP DATABASE mirthdb command and the identity/session that issued it. If logging or auditing wasn’t enabled, the customer-visible evidence may be limited.

At this point, open an Azure Database Migration Service support case and provide the migration workflow ID, target server name, database name, cancellation timestamp, source/target regions, and the Activity Log entries. Ask the DMS team to inspect backend workflow logs and confirm whether its cancellation cleanup removed the database.

The missing ARM delete event is secondary noise here. The real issue is that the target database disappeared immediately after the migration cancellation, and only DMS backend logs can confirm why.

rgds,

Alex

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