Deciding when to use Azure Blobs, Azure Files, or Azure Disks

Microsoft Azure provides several features in Azure Storage for storing and accessing your data in the cloud. This article covers Azure Files, Blobs, and Disks, and is designed to help you choose between these features.


The following table compares Files, Blobs, and Disks, and shows example scenarios appropriate for each.

Feature Description When to use
Azure Files Provides an SMB interface, client libraries, and a REST interface that allows access from anywhere to stored files. You want to "lift and shift" an application to the cloud which already uses the native file system APIs to share data between it and other applications running in Azure.

You want to store development and debugging tools that need to be accessed from many virtual machines.
Azure Blobs Provides client libraries and a REST interface that allows unstructured data to be stored and accessed at a massive scale in block blobs.

Also supports Azure Data Lake Storage Gen2 for enterprise big data analytics solutions.
You want your application to support streaming and random access scenarios.

You want to be able to access application data from anywhere.

You want to build an enterprise data lake on Azure and perform big data analytics.
Azure Disks Provides client libraries and a REST interface that allows data to be persistently stored and accessed from an attached virtual hard disk. You want to lift and shift applications that use native file system APIs to read and write data to persistent disks.

You want to store data that is not required to be accessed from outside the virtual machine to which the disk is attached.

Comparison: Files and Blobs

The following table compares Azure Files with Azure Blobs.

Attribute Azure Blobs Azure Files
Durability options LRS, ZRS, GRS, RA-GRS LRS, ZRS, GRS
Accessibility REST APIs REST APIs

SMB 2.1 and SMB 3.0 (standard file system APIs)
Connectivity REST APIs -- Worldwide REST APIs - Worldwide

SMB 2.1 -- Within region

SMB 3.0 -- Worldwide
Endpoints \\\myshare\myfile.txt
Directories Flat namespace True directory objects
Case sensitivity of names Case sensitive Case insensitive, but case preserving
Capacity Up to 2 PiB Account Limit 5 TiB file shares
Throughput Up to 60 MiB/s per block blob Up to 60 MiB/s per share
Object Size Up to about 4.75 TiB per block blob Up to 1 TiB per file
Billed capacity Based on bytes written Based on file size
Client libraries Multiple languages Multiple languages

Comparison: Files and Disks

Azure Files complement Azure Disks. A disk can only be attached to one Azure Virtual Machine at a time. Disks are fixed-format VHDs stored as page blobs in Azure Storage, and are used by the virtual machine to store durable data. File shares in Azure Files can be accessed in the same way as the local disk is accessed (by using native file system APIs), and can be shared across many virtual machines.

The following table compares Azure Files with Azure Disks.

Attribute Azure Disks Azure Files
Scope Exclusive to a single virtual machine Shared access across multiple virtual machines
Snapshots and Copy Yes Yes
Configuration Connected at startup of the virtual machine Connected after the virtual machine has started
Authentication Built-in Set up with net use
Access using REST Files within the VHD cannot be accessed Files stored in a share can be accessed
Max Size 32 TiB disk 5 TiB File Share and 1 TiB file within share
Max IOps 20,000 IOps 1000 IOps
Throughput Up to 900 MiB/s per Disk Target is 60 MiB/s per File Share (can get higher for higher IO sizes)

Next steps

When making decisions about how your data is stored and accessed, you should also consider the costs involved. For more information, see Azure Storage Pricing.

Some SMB features are not applicable to the cloud. For more information, see Features not supported by the Azure File service.

For more information about disks, see our Introduction to managed disks and How to Attach a Data Disk to a Windows Virtual Machine.