What Are CDM Folders and How They Work with Azure Blob in Power BI

Many people want to bring their data into Power BI, but using storage accounts or folder formats can feel confusing. I often hear from users who store files in Azure Blob but are not sure how to connect that data to their reports. This is where CDM folders can really help.

A CDM folder is a special type of structure that gives the reporting tool clear details about your data. It tells the platform what the data is, how it is organized, and how different parts are linked. In this article, I will explain:

What this format is
Why does it work well with Azure Blob
How to use it in your reports

What Is the Common Data Model (CDM)?

The Common Data Model, or CDM, is a way to organize and describe data in a clear format. It uses standard terms so that different systems can understand the same data.

You can think of it as a list of shared rules that explain:

What each data table means (like “Customer” or “Sales”)
What each column stands for (like “Name” or “Amount”)
How are the different tables related to each other

This format helps reporting tools like Power BI read and show your information without guessing. CDM folders follow this model so files can be used across tools like Dataverse and other connected services.

CDM Folder Structure Explained

A folder using the CDM format is more than just a collection of files. It includes certain parts that help the reporting tool understand what it is working with. Key components include:

A manifest file (named manifest.cdm.json) that lists the tables and their details
Entity folders that hold the actual data (usually in CSV or Parquet)
Metadata that explains the structure and relationships

This setup helps platforms like Power BI recognize what each file represents and how everything is connected. Without this setup, the system would only see raw files with no context.

Why Use Azure Blob for Storing CDM Folders

Azure Blob is a reliable place to store large amounts of structured data. It’s flexible, cost-effective, and works well with Microsoft services. When you save CDM-formatted folders here, both the data and its structure stay together in one place.

Here’s why many users prefer using Azure Blob for this purpose:

It scales easily as data grows
It works with tools like Power Apps, Dataverse, and Azure Data Factory
It supports secure access through keys or tokens
It connects smoothly with Power BI through its native connector

Many services can write to Blob Storage in CDM format, so there’s no need to manually manage files or schema.

How Power BI Reads CDM Folders

The platform includes a built-in option called Common Data Model that lets users connect directly to folders stored in Azure Blob. You only need the folder path and access details to begin.

Here’s what happens during the connection process:

The system finds the manifest file
It checks which tables are listed
You choose the tables you want to load
Relationships are recognized and applied to your report

This makes the process much easier than using raw file imports. Because the model includes metadata, the platform already understands what your data means and how the pieces fit.

Where CDM Folders Are Used in Practice

This format is used in many day-to-day situations. One common case is exporting business data from tools like Dataverse into Azure Blob. It allows reporting teams to build dashboards without cleaning or reshaping the data each time.

Here are some practical examples:

Data teams save reusable models in Blob Storage for others to access
Businesses use Azure Data Factory or Synapse to automate exports
Analysts build reports directly on top of structured data using this format

This approach improves speed, accuracy, and teamwork.

What’s Next: Connecting CDM to Power BI

Now that you understand what CDM is and how it fits with Azure Blob, the next step is to connect everything inside Power BI. You’ll need to set up access, provide the folder path, and use the right connector to bring your data into reports.

To set it up, follow this CDM to Power BI connection guide. It covers each step clearly, so you can start using your data without confusion.

Conclusion

The CDM model helps bridge structured data stored in Azure Blob with tools like Power BI. It adds meaning to your files and simplifies the connection process. Once you understand how the format works, using it becomes much easier.

If you’re ready to move forward, the next article will show you how to connect and start building your own reports.

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