Forum Discussion
ADF dataflow data Preview Error
hi All,
I have data flow as seen below. all linked service and data set working fine and i can see the data preview but wheb i use the same linked service and dateset in the dataflow It throw error as shown below i am useing managed private endpoint to coonect the blob starga it is owrking for all pipe line. the ADF and the MI has staorgae account contributor role assigned.
Error:
at Source 'sourcedata': This request is not authorized to perform this operation. When using Managed Identity(MI)/Service Principal(SP) authentication 1. For source: In Storage Explorer, grant the MI/SP at least Execute permission for ALL upstream folders and the file system, along with Read permission for the files to copy. Alternatively, in Access control (IAM), grant the MI/SP at least the Storage Blob Data Reader role. 2. For sink: In Storage Explorer, grant the MI/SP at least Execute permission for ALL upstream folders and the file system, along with Write permission for the sink folder. Alternatively, in Access control (IAM), grant the MI/SP at least the Storage Blob Data Contributor role. Also please ensure that the network firewall settings in the storage account are configured correctly as turning on firewall rules for your storage account blocks incoming requests for data by default, unless the requests originate from a service operating within an Azure Virtual Network (VNet) or from allowed public IP addresses.
Any kind of help is highly appreciated
1 Reply
I assume you're getting this error because ADF Data Flow preview runs on a separate debug cluster, which doesn’t use your private endpoint.
To fix it:
- Assign IAM role Storage Blob Data Reader to the ADF Managed Identity at the container level.
- If using ADLS Gen2, grant ACLs: Execute on parent folders and Read on the file(s).
- Ensure the storage firewall allows access from "Trusted Microsoft services" or configure VNet + private endpoint for data flow debug.
Transform data with an Azure Data Factory managed virtual network mapping data flow - Azure Data Factory | Microsoft Learn
