We’re using Cloud SQL for PostgreSQL with about 13TB of provisioned storage. After a cleanup of old data, our actual usage is now under 7TB — but the disk size remains locked at 13TB because Cloud SQL doesn’t support shrinking disk size.
This leads to unnecessary costs and makes it harder to manage long-lived, large-scale databases efficiently.
Feature requests:
• Add support to manually reduce disk size after data cleanup.
• Allow restoring backups to a smaller disk, based on current data size instead of historical max size.
• Provide a simple built-in method to migrate to a smaller instance, without relying entirely on DMS (which doesn’t always work in complex cases).
While you can’t shrink the disk directly from the Cloud SQL console, there are two options available to right-size your storage:
Option 1: Contact Google Cloud Support
The most straightforward path is to open a ticket with Google Cloud Support. Their team can use an internal tool to shrink the data disk of your existing instance. This is usually the quickest and simplest way to adjust storage without having to manage a migration yourself.
Option 2: Migrate to a New, Right-Sized Instance
If you’d like a self-service approach, you can:
Create a new Cloud SQL instance with the desired smaller disk size (for example, 7TB).
Use Database Migration Service (DMS) or the native export/import functionality to move your data.
Cut over your application to the new instance once migration is complete.
As Cloud SQL currently does not support shrinking disk size, I suggest filing this as a feature request. Please note that I cannot provide specific details or timelines regarding future availability. However, you may monitor the release notes for any updates or new features related to Cloud SQL, as improvements to storage management are typically announced there.