Cosmos DB for PostgreSQL -> Elastic Cluster migration blocked: "current disk configuration is not supported"

Question

Cosmos DB for PostgreSQL -> Elastic Cluster migration blocked: "current disk configuration is not supported"

Dmitrii Bocharov 20

I'm trying to migrate an Azure Cosmos DB for PostgreSQL cluster to Azure Database for PostgreSQL (Elastic Cluster) using the Migration blade in the portal, and it's blocked with:

"Cluster is not eligible for migration. Migration can not be started because of the following prerequisite(s): - Migration with the current disk configuration is not supported. Please file a support ticket."

Cluster details:

Single-node configuration
PostgreSQL 16 / Citus 12.1
Region: Germany West Central

Our actual production db is on Postgres 15 (citus 11.1). And the previous error was: "Only clusters with PostgreSQL version 16 and Citus version 12.1 can be migrated". In order to safely test the upgrade and migration, i've created a point-in-time-restore copy of the cluster and upgraded the copy to PostgreSQL 16 / Citus 12.1. On the upgraded copy, the version prerequisite is cleared and the ONLY remaining blocker is the identical "current disk configuration is not supported" message. So the disk configuration appears to be inherited from the cluster's storage layout (the restore preserves it), and upgrading the Postgres/Citus version alone does not resolve it.

My questions:

What specifically about the "current disk configuration" makes a cluster ineligible for migration to Elastic Cluster?
Is there a way to remediate this myself, or does it strictly require Microsoft to update the storage layout on the backend?
Does this typically clear automatically after a scheduled maintenance event, or is manual intervention always required?
Has anyone successfully gotten past this error, and if so, how?

Any guidance appreciated - thanks!

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2 answers

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Answer 1

Hi @Dmitrii Bocharov
Thanks for sharing the details.

Since you've already upgraded the PITR copy to PostgreSQL 16 / Citus 12.1 and the version prerequisite has been cleared, the remaining blocker appears to be an internal migration eligibility check related to the source cluster's storage configuration.

At this time, Microsoft documentation does not publicly describe which specific disk attributes make a Cosmos DB for PostgreSQL cluster ineligible for migration to Azure Database for PostgreSQL Elastic Cluster, nor is there a documented self-service remediation for this prerequisite check.

Because a Point-in-Time Restore preserves the original cluster configuration, upgrading PostgreSQL/Citus versions alone may not change the underlying storage characteristics used by the migration eligibility validation.

There is also no documented evidence that this issue resolves automatically during scheduled maintenance.

To gather more information, please check whether the cluster is in a Ready state and review the Activity Log and Deployment details in the Azure portal for any additional error codes or diagnostic messages associated with the migration attempt.

Based on the information shared so far, this appears to be a migration eligibility limitation rather than a PostgreSQL/Citus version issue, but additional investigation would be needed to determine the exact cause.

Pilladi Padma Sai Manisha 10,770 Reputation points Microsoft External Staff Moderator

2026-06-19T09:25:28.3333333+00:00

Hi @Dmitrii Bocharov
Following up to see if the below answer was helpful. If this answers your query, do click Accept Answer and Yes for was this answer helpful. And, if you have any further query do let us know.

Answer 2

The error message about “current disk configuration is not supported” for Cosmos DB for PostgreSQL → Elastic Cluster migration is not described in the provided documentation, and the context does not specify which disk layouts are eligible or how to change them.

The available documentation only covers at a high level:

That Azure Cosmos DB for PostgreSQL is on a retirement path and that Elastic Clusters in Azure Database for PostgreSQL are the recommended target for PostgreSQL workloads.
General concepts such as compute and storage, maintenance, upgrades, and authentication.

It does not describe:

Which specific disk configurations block migration.
Any self-service way to change the disk layout of an existing Cosmos DB for PostgreSQL cluster to make it eligible.
Whether scheduled maintenance can automatically change the disk configuration to an eligible one.
Any known workaround or success pattern for this specific “current disk configuration is not supported” migration blocker.

Because of this, the only supported guidance from the available material is to follow the message’s instruction to file a support ticket so that Microsoft can inspect and, if possible, adjust the backend configuration of the cluster.

References: