Unable to disable Fabric Mirroring on PostgreSQL Flexible Server — Burstable SKU conflict

The supported disable operations have already been exhausted; because azure.fabric_mirror_enabled is workflow-managed and every disable path is rejected by the SKU validator, this state requires investigation by the Azure Database for PostgreSQL service team rather than another parameter or CLI attempt.

What is established

• Standard_B1ms belongs to the Burstable compute tier, which cannot be used as a Fabric Mirroring source; only General Purpose and Memory Optimized tiers are supported.^1^
• azure.fabric_mirror_enabled defaults to off, is set automatically by the mirroring enablement workflow, and should not be changed manually.^2^
• az postgres flexible-server fabric-mirroring stop is the documented GA server-level stop operation.^3^

The documentation does not describe MirroringNotSupportedForBurstableSku occurring during a stop operation, nor does it publish a force-reset command. Therefore, the exact behavior cannot be confirmed publicly as a known defect, but it is consistent with an inconsistent control-plane state: the server is marked enabled while its current SKU prevents the control plane from processing the operation intended to clear that state.

Do not keep editing the parameter, alter mirroring prerequisites, or recreate mirroring artifacts. Those actions are not documented as a reset mechanism and could add database-level CDC state without clearing the server-level flag.

Escalate with a reproducible service request

1. In Azure Portal, open Help + support → Create a support request.
2. Select:
   • Issue type: Technical
   • Service: Azure Database for PostgreSQL Flexible Server
   • The subscription containing the affected server
3. Include:
   • Current SKU: Standard_B1ms
   • Server state: Ready
   • Parameter: azure.fabric_mirror_enabled = on
   • Source: user-override
   • Exact error: MirroringNotSupportedForBurstableSku
   • Approximate UTC timestamps and correlation/request IDs from failed operations
   • Confirmation that Portal, direct parameter update, allowlist removal, and the GA CLI stop operation all failed
   • Confirmation that no Fabric mirrored database currently exists
   • Business impact: Entra authentication configuration is blocked
4. Request that the case be routed to the Azure Database for PostgreSQL Flexible Server control-plane/Fabric Mirroring engineering team to reconcile or clear the server-level mirroring state without changing the compute tier or credentials.

Azure’s support workflow allows logs or a browser trace to be attached and recommends supplying reproduction details and timestamps for routing.^4^

If the Basic plan redirects the technical request to Microsoft Q&A, use Priority Community Support when the portal offers it. Eligible requests retain a tracking ticket linked to the Q&A thread, and an Azure engineer can move customer-specific investigation to a private message or associated email conversation.^5^ Do not post the server name, subscription ID, resource ID, logs containing tokens, or credentials publicly.

Backend mitigation has been used for other PostgreSQL Flexible Server resources stuck in control-plane states, but those reports concern different operations and do not establish the required correction for this mirroring error.^6^

Optional evidence for the service team

Without changing anything, capture the database-level CDC state:

SELECT * FROM azure_cdc.tracked_publications;
SELECT * FROM pg_replication_slots;

These are documented diagnostic queries for determining whether publications and replication slots remain active.^7^ An empty result would support the distinction between “no active database replication” and the stuck server-level control-plane flag.

The available documentation does not establish that enabling Microsoft Entra authentication depends on Fabric Mirroring being disabled. Report that failure as a second symptom, including its exact operation and error response, rather than assuming the mirroring flag is its cause. Current PostgreSQL documentation states that both Entra ID and local database roles can be used with Fabric Mirroring, so their coexistence is not documented as inherently unsupported.^2^

References

1. Mirroring Azure Database for PostgreSQL flexible server
2. Azure Database for PostgreSQL flexible server mirroring in Microsoft Fabric
3. az postgres flexible-server fabric-mirroring | Microsoft Learn
4. Create an Azure support request
5. Get Azure help through Priority Community Support (PCS)
6. Azure Database for PostgreSQL flexible server stuck in stopping state - need assistance recovering - Microsoft Q&A
7. Troubleshoot Fabric mirrored databases from Azure Database for PostgreSQL flexible server