What are Block Blobs, Append Blobs, and Page Blobs?

Azure Blob Storage is a cloud-based storage solution that enables developers to store and manage large amounts of unstructured data. Blob storage can store any type of text or binary data, such as documents, images, audio, and video files. Blobs are divided into three types: block blobs, append blobs, and page blobs. Each type of blob has its unique characteristics and is used for different purposes.

In this article, we will take an in-depth look at block blobs, append blobs, and page blobs, their characteristics, and when to use them. Let’s get started!


Cloud Storage Manager Reports Tab

Block Blobs:

Block blobs are the most common type of blob and are used to store large amounts of data. A block blob can be thought of as a collection of blocks that can be uploaded in parallel. Each block can be a maximum of 100 MB in size, and a block blob can contain up to 50,000 blocks.

Block blobs are ideal for scenarios where you need to upload large files or data streams, such as media files or backups. They are also useful in scenarios where you need to update or append to an existing file. Block blobs are optimized for read and write operations and provide efficient data transfer.

Some of the key characteristics of block blobs include:

  • Block blobs are made up of blocks that can be uploaded in parallel
  • Each block can be a maximum of 100 MB in size
  • Block blobs can contain up to 50,000 blocks
  • Block blobs are optimized for read and write operations

When to Use Block Blobs?

Block blobs are ideal for scenarios where you need to upload large files or data streams, such as media files or backups. They are also useful in scenarios where you need to update or append to an existing file.

Append Blobs:

Append blobs are similar to block blobs, but they are designed for scenarios where data needs to be added to an existing blob. Append blobs are optimized for append operations and are made up of blocks that are optimized for append-only scenarios.

Append blobs are ideal for scenarios where you need to add data to a file over time, such as log files. Append blobs provide efficient data transfer and ensure that the data is written in the order in which it was received.

Some of the key characteristics of append blobs include:

  • Append blobs are made up of blocks that are optimized for append-only scenarios
  • Data can only be added to an append blob, not modified or deleted
  • Append blobs are optimized for append operations and ensure that data is written in the order it was received
  • Append blobs can contain up to 50,000 blocks

When to Use Append Blobs?

Append blobs are ideal for scenarios where you need to add data to a file over time, such as log files.

Page Blobs:

Page blobs are used to store random access files, such as virtual hard disks (VHDs) used by virtual machines. Page blobs are optimized for random read-write operations and are made up of 512-byte pages.

Page blobs are ideal for scenarios where you need to access and modify data in random locations, such as when working with VHDs. They provide low latency random access and are optimized for data that changes frequently.

Some of the key characteristics of page blobs include:

  • Page blobs are optimized for random read-write operations
  • Data in page blobs is organized into 512-byte pages
  • Page blobs are ideal for storing VHDs used by virtual machines
  • Page blobs can contain virtual hard disks (VHDs) that are used to store the operating system, applications, and data for virtual machines in Azure. They are optimized for random read and write operations and can support up to 8 TB of data. Page blobs are typically used for scenarios where data needs to be accessed randomly, such as storing VHDs for virtual machines or for disk-to-disk backups.

When to Use Page Blobs?

Page blobs are ideal for scenarios where you need to access and modify data in random locations, such as when working with VHDs.

Differences between Block Blobs, Append Blobs, and Page Blobs:

To summarize, the main differences between block blobs, append blobs, and page blobs are:

  • Block blobs are ideal for uploading large files or data streams, updating or appending to an existing file, and optimizing for read and write operations.
  • Append blobs are ideal for scenarios where you need to add data to a file over time, such as log files, and optimizing for append operations.
  • Page blobs are ideal for storing random access files, such as VHDs used by virtual machines, and optimizing for random read-write operations.

Page, Block and Append Blob Comparison

Blob Type Block Blob Append Blob Page Blob
Use case
Storing large files, streaming data Logging, continuously adding data to an existing blob Storing virtual hard disk (VHD) files
Max size
190.7 TiB 195 GB 8 TiB
Upload method
Uploaded in blocks, can be uploaded in parallel Appended to sequentially Uploaded in a single operation
Read method
Random access, read any block of data at any time Sequential access, read data in order it was written Random access, read any portion of the blob
Data modification
Can modify individual blocks Can only append new data Can modify individual pages
Pricing model
Based on storage size and number of operations Based on storage size and number of append operations Based on storage size and number of operations

Page, Block and Append Blob FAQs

Question Answer
What are the different blob types?
The different blob types are block blobs, append blobs, and page blobs.
What is an append blob?
An append blob is a type of blob in Azure that allows for adding data to the end of an existing blob.
What is the difference between block blob, append blob, and page blob in Azure?
Block blobs are optimized for streaming and storing large amounts of data, append blobs allow for adding data to the end of an existing blob, and page blobs are optimized for random read and write operations.
What is the limit of page blob in Azure?
The maximum size of a page blob in Azure is 8 TB.
What is the difference between blob storage and ADLs?
Blob storage is optimized for storing unstructured data, while ADLs (Azure Data Lake Storage) is optimized for big data analytics workloads.
What is Blob and block storage?
Blob storage is a type of storage in Azure that allows for storing large amounts of unstructured data, while block storage is a type of storage that allows for storing and retrieving data in blocks.
What are four types of storage available in Azure storage?
The four types of storage available in Azure storage are blob storage, file storage, table storage and queue storage.
What is the difference between Blob storage and table storage?
Blob storage is optimized for storing unstructured data, while table storage is optimized for storing structured NoSQL data.
What is the difference between S3 and blob storage?
S3 is Amazon Web Services’ (AWS) object storage service, while blob storage is Microsoft Azure’s object storage service.
What are the tiers of blob storage and how do they work?
The tiers of blob storage in Azure are hot, cool, and archive. Hot storage is for frequently accessed data, cool storage is for infrequently accessed data, and archive storage is for long-term retention of rarely accessed data.
What is Tier 1, Tier 2, and Tier 3 storage?
Tier 1, Tier 2, and Tier 3 storage refer to different levels of storage performance and cost. Tier 1 is typically the highest performance and highest cost, while Tier 3 is typically the lowest performance and lowest cost.
What are the three tiers of storage?
The three tiers of storage are Hot, Cool and archive.
What type of storage is blob?
Blob is a type of object storage.
What is page blob?
Page blob is a type of blob in Azure that allows for random read and write operations.
Why use block storage?
Block storage is useful for workloads that require high-performance storage and fast access times, such as databases or virtual machines.
What does blob stand for?
Blob stands for “binary large object.”
Where are BLOBs stored?
BLOBs are stored in object storage systems such as Azure Blob storage or AWS S3.
Is BLOB the same as buffer?
No, BLOB and buffer are not the same. A buffer is a temporary storage area used for data transfer, while a BLOB is a type of data that can be stored in a database or object storage system.
How can I save money with my Azure Storage
Use Cloud Storage Manager to understand your Azure Storage Consumption. Find how much data you are actually consuming and view reports to start saving money.
What is the difference between block and file storage?
Block storage is optimized for storing and retrieving data in blocks, while file


Cloud Storage Manager Top 100 Blobs Tab

Page, Block and Append Blob Final Thoughts

In conclusion, understanding the differences between block blobs, append blobs, and page blobs is important when working with Azure Blob Storage. Each type of blob has its unique characteristics and use cases, and choosing the right type of blob can help optimize your data storage and access. Whether you are uploading large files, adding data to a file over time, or storing random access files, Azure Blob Storage has a type of blob that can meet your needs.

Azure Storage Unlocked

Please fill out the form below to get our free Ebook "Azure Storage Unlocked" emailed to you
FREE DOWNLOAD

Send download link to:

I confirm that I have read and agree to the End User License Agreement.