Microsoft Azure Docs

Azure Blob Storage Overview

Azure Blob Storage is Microsoft's object storage solution for the cloud. It's optimized for storing massive amounts of unstructured data, such as text or binary data.

What is Blob Storage?

Unstructured data is data that doesn't adhere to a particular data model or definition, such as text or binary files. Blob storage is ideal for:

• Serving images or documents directly to a browser.
• Storing files for distributed access.
• Streaming video and audio.
• Writing to log files.
• Storing data for backup, restore, disaster recovery, and archiving.
• Storing data for analysis by an on-premises or Azure-hosted service.

Key Concepts

A storage account provides a unique namespace in Azure for your data. Every object that you can store in Azure Storage has at least one storage account associated with it. The total limit of a storage account is determined by the account type.

• Blob: A blob can be any kind of text or binary data. Blobs are the objects that make up the data stored in Azure Blob Storage.
• Container: A container is a logical grouping of a set of blobs. You must create a container before you can upload a blob into storage.
• Storage Account: A storage account gives you access to Azure Storage data objects, which are publicly accessible from anywhere in the world via HTTP or HTTPS. Each account has a unique name that serves as its domain.

Blob Types

Azure Blob Storage supports three types of blobs:

• Block blobs: Optimized for storing large amounts of unstructured data, such as documents or media files. Block blobs are made up of blocks of data that can be uploaded independently and in any order.
• Append blobs: Optimized for append operations, such as writing to log files. When you need to add data to an existing blob, you can use an append blob.
• Page blobs: Optimized for random read and write operations. Page blobs are used to store virtual hard disk (VHD) files for Azure virtual machines.

Access Tiers

Azure Blob Storage offers different access tiers to store data at the right price for how frequently it's accessed:

• Hot: Optimized for frequently accessed data.
• Cool: Optimized for infrequently accessed data and available for at least 30 days.
• Archive: Optimized for rarely accessed data and available for at least 180 days with flexible latency requirements.

You can set the access tier for a storage account or for individual blobs. This allows you to optimize costs by moving data between tiers based on access patterns.

// Example of uploading a blob (conceptual, not actual SDK code)
const blobService = new AzureStorage.BlobServiceClient(connectionString);
const containerClient = blobService.getContainerClient("mycontainer");
const blockBlobClient = containerClient.getBlockBlobClient("myblob.txt");

const uploadResponse = await blockBlobClient.upload(data, data.length);
console.log(`Blob uploaded successfully: ${uploadResponse.requestId}`);
                

Security

Azure Blob Storage offers robust security features, including:

• Azure Active Directory (Azure AD) integration: For role-based access control.
• Shared Access Signatures (SAS): For delegated access to resources.
• Encryption: Data is encrypted at rest by default with 256-bit AES encryption.
• Network Security: Firewalls and virtual networks can restrict access.

Getting Started

To start using Azure Blob Storage, you'll need to:

1. Create an Azure Storage Account: You can do this through the Azure portal, Azure CLI, or PowerShell.
2. Create a Container: Organize your blobs within containers.
3. Upload Data: Use the Azure SDKs, REST API, Azure Storage Explorer, or Azure portal to upload your files.

Explore the Blob Storage Quickstart to begin.