What causes DF-SQLDW-InvalidStorageType?

The staging linked service is set to a storage type other than Azure Blob Storage or ADLS Gen2 — for example Azure Files, Amazon S3, or FTP. A dataset for a non-blob storage resource was accidentally selected as the staging configuration. The staging linked service was recently changed and now points to an incompatible storage type. The pipeline was cloned from a template that used a different connector, and the staging storage was not updated

How do I fix DF-SQLDW-InvalidStorageType?

Open the failing data flow in ADF Studio and go to Synapse Analytics sink settings.. In the sink Settings tab, locate the Staging linked service field and click it to open the linked service.. Check the linked service type — it must be Azure Blob Storage or Azure Data Lake Storage Gen2; any other type causes this error.. If the type is wrong, create a new linked service of type Azure Blob Storage or ADLS Gen2 pointing to a staging storage account in the same Azure region as the Synapse workspace.. Select the corrected linked service in the sink staging settings and re-run the data flow.. ADLS Gen2 is the preferred staging type for Synapse workspaces — it is Synapse's native storage tier and delivers better performance than Blob Storage.

Medium severityconfiguration

Power BI Refresh Error:
DF-SQLDW-InvalidStorageType

What does this error mean?

The staging storage for Synapse Analytics uses an unsupported type. COPY INTO and PolyBase staging only support Azure Blob Storage or ADLS Gen2 — Azure Files, Amazon S3, SFTP, and others are not supported.

Common causes

1The staging linked service is set to a storage type other than Azure Blob Storage or ADLS Gen2 — for example Azure Files, Amazon S3, or FTP
2A dataset for a non-blob storage resource was accidentally selected as the staging configuration
3The staging linked service was recently changed and now points to an incompatible storage type
4The pipeline was cloned from a template that used a different connector, and the staging storage was not updated

How to fix it

1Open the failing data flow in ADF Studio and go to Synapse Analytics sink settings.
2In the sink Settings tab, locate the Staging linked service field and click it to open the linked service.
3Check the linked service type — it must be Azure Blob Storage or Azure Data Lake Storage Gen2; any other type causes this error.
4If the type is wrong, create a new linked service of type Azure Blob Storage or ADLS Gen2 pointing to a staging storage account in the same Azure region as the Synapse workspace.
5Select the corrected linked service in the sink staging settings and re-run the data flow.
6ADLS Gen2 is the preferred staging type for Synapse workspaces — it is Synapse's native storage tier and delivers better performance than Blob Storage.

Frequently asked questions

Why does writing to Synapse require staging storage at all?

Synapse uses PolyBase or COPY INTO for bulk loads — both require staging in Blob/ADLS Gen2 first. ADF writes to staging, then Synapse loads from there. Direct row-by-row inserts are too slow for analytical workloads.

Can I use ADLS Gen1 as staging for Synapse?

No — ADLS Gen1 is not supported as Synapse staging storage. ADLS Gen1 was retired in February 2024. Use ADLS Gen2 (with Hierarchical Namespace enabled) or Azure Blob Storage instead.

Does the staging storage need to be in the same region as the Synapse workspace?

Yes — staging storage in a different region from the Synapse workspace causes cross-region data transfer, which significantly increases latency and incurs additional costs. Always use staging storage co-located with the Synapse workspace.

Will downstream Power BI datasets be affected?

Yes — the Synapse write fails completely, leaving the target table with stale or no data. Dependent datasets will show outdated figures.

Official documentation: https://learn.microsoft.com/en-us/azure/data-factory/data-flow-troubleshoot-guide