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Azure Blob storage spindle

Azure Blob Storage

Blobs, Blobs and more Blobs.

If you have ever had the need to store large amounts of files and data, then Azure’s Blob Storage is made for you. 

Microsoft’s Azure Cloud provides huge benefits with not only their fantastic services, locations, availability and support, but also in their almost seemingly infinite capacity. 

Azure Blob Storage is not only scalable, durable and almost always available it also provides flexibility to scale as your business requirements need. 

A huge benefit to using Azure services is the pay as you go service model, that allows you to only pay for the services you consume. No more need to over provision local file servers hard drives for expected capacity, with Azure Blob Storage you upload your files to Azure and only pay for the space you need.

Azure Blob Storage

What is Azure Blob Storage?

Azure Blob Storage Overview

Azure Blob Storage (Blob stands for Binary Large Object) is storage provided by Microsoft’s Azure for unstructured data. Perfect for massive amounts of data. Example use cases are as a target for your log or analytics data, or Blob Storage can be used as a backup and archival location, and even things like files, pictures and music files. Basically Azure Blob Storage is a great dumping ground for huge amounts of your data.

A Blob is actually a file which is stored in a directory like structure called a Container, then within an Azure Storage Account, and an Azure Resource Group and finally an Azure Subscription.

Access to each Azure Blob is provided by a HTTPS link directly to the Blob itself, meaning you can access the file from anywhere in the world with an internet connection. Obviously if you dont want the data exposed to the whole world, you can lock this down to meet your security needs.

Azure Blob Storage Unstructured Data

Azure Blob Storage Hierachy

Azure Resource Group

An Azure Resource Group is used to contain related resources together for a solution.

Resource Groups can not only contain storage accounts, but its a logical collection of configuration items within Azure. From Virtual Machines to Virtual Networks, it groups together items in a logical container. 


Azure Storage Acounts

An Azure Storage Account is the top level of Storage Services within Azure. 

The Storage Account contains all your Azure Storage items, including Blobs, Queue Tables, File Shares and your VIrtual Machine’s disks. 

As Azure is Cloud based, you can access this storage from anywhere in the world with an internet connection.

There is a default limit of 250 Storage Accounts per region and per subscription, with no limits on the number of Azure Storage Containers or Blobs contained within.

Azure Storage Containers

 Azure Storage Containers are used like a folder, (in the sense of the old WIndows File System), that contains all your blobs. 

You can have an unlimited amount of Storage Containers per Storage Account.

Azure Blobs

What is a Blob?

Lastly, an Azure Blob (or as it can be known, Binary Large Object) is any type of file, is unstructured and will be stored within an Azure Storage Container.

You can store large amounts of Blobs within each container, and these could be things like document files, images and other multimedia.

Azure Blob Storage Configurations and Options

Azure Blob Storage Tiering

Microsoft provides different storage tiering models for the storing of your data

Each one has a different storage pricing model in Azure (per GB) and access requirements.

  • Hot – Best for data that  is accessed frequently. (most expensive per GB)
  • Cool – Great for data that is accessed infrequently. (not as expensive as Hot, but no where as cheap as the Archive Tier)
  • Archive – Perfect for data that is very rarely accessed. (cheapest per GB)

Azure Blob Storage Types

Azure Blob Storage has three different types

These are;

  • Block Blobs – Perfect for storing documents, text files or even your media files
  • Append Blobs – cannot be modified and requires you to upload a new blob. 
  • Page Blobs – are used for storing Azure Virtual Machine disks.

Azure Blob Storage Availability

Additionally when creating your Azure Storage Account you can choose how much redundancy / availability for your Azure Blob Storage. While Microsoft provides an SLA on the uptime of your storage, choosing the correct availability of your Azure Storage Account will ensure your Azure Blobs are accessible in the event of failure.

  • LRS – Locally Redundant Storage – Keeps a synchronous copy of your Azure Blobs three times within the same Azure Datacentre. This is the least cost option
  • ZRS – Zone Redundant Storage – Replicates your Azure Blobs synchronous across three Azure Availability Zones in the primary region.
  • GRS – Geo-Redundant Storage– Copies your Azure Blobs synchronous three times within the same Azure Datacentre, then copies the same Azure Blobs asynchronously across to  one other single location in another secondary Azure Region.
  • GZRS – Geo-Zone-Redundant Storage– Copies your Azure Blobs synchronous across three Azure Availability Zones in the primary region, then copies the same Azure Blobs asynchronously across to  one other single location in another secondary Azure Region.

Azure Blob Storage Limitations

Although Azure Blob Storage seems limitless, there are always some technical limitations that you should be aware of.

Some of these limitations are;

  • Service Level Agreement – Microsoft provides an uptime 99.99% on Azure Blob Storage
  • Maximum size of Storage Account – 500TB
  • Maximum size of a Single Blob – 5TB
  • Number of Blocks in a Blob – 50,000 blocks
  • Maximum size of a block – 100MB
  • Minimum size of a block – 64KB
  • Maximum Storage Account Capacity – 5PB
  • Number of Storage Accounts per Subscription – 200
  • Tiering – Only the Hot and Cool Access Tiers can be set at the root of the Storage Container. Archive Tier is per individual Blob. (you can select multiple files using Cloud Storage Manager to change to the Archive Tier. This isnt possible using the Azure Portal)
  • Archive Tier stores the data offline. This requires time to retrieve the Blob from the offline storage. There is additional cost to retrieve this data and the retrieval time can take several hours.
  • Archive Tier Rehydration – When a Blob is in the Archive Tier the data cannot be modified as it is actually offline. To modify a Blob in this Tier you would first need to rehydrate the Blob to an Online Tier (Hot or Cool)

Azure Blob Storage Pricing

As with anything cloud-based, be careful which options you select as there will be cost impacts. As an example, Locally Redundant Storage is the cheapest availability option for Microsoft’s Azure Blob Storage, whereas Geo Zone Redundant Storage provides the highest Availability, but costs significantly more.

For Azure Blob Tiering, the Archive Tier is the cheapest at almost a tenth of the cost of Cool and Hot Tiers..



TieringLRS – Locally Redundant StorageZRS – Zone Redundant StorageGRS – Geo-Redundant StorageRA-GRS – Read Access Geo-Redundant StorageGZRS – Geo Zone Redundant StorageRA-GZRS – Read Access Geo Zone Redundant Storage
Blob Storage – Archive Tier0.03 cents for 10GBOption not available for Archive Tier0.07 cents for 10GB0.07 cents for 10GBOption not available for Archive TierOption not available for Archive Tier
Blob Storage – Cool Tier0.21 cents for 10GB0.26 cents for 10GB0.41 cents for 10GB0.53 cents for 10GB0.48 cents for 10GB0.60 cents for 10GB
Blob Storage – Hot Tier0.28 cents for 10GB0.35 cents for 10GB0.56 cents for 10GB0.70 cents for 10GB0.66 cents for 10GB0.82 cents for 10GB

Now while the price does fluctutate at times, and even differentiates between the different Microsoft Azure Datacentres, the pricing table above has been given as a reference to the differences in costs and options on your Azure Storage.

To work out how much the cost differences, you can use the Microsoft Azure Pricing Calculator to work out the cost impacts to your solution

Do you want information on all your Blobs in Azure?

Azure Blob Storage Insights

Now that you have some background in to what Azure Blob Storage can do for you and are ready to take the jump and start uploading huge amounts of data to your Azure Storage Containers.

Cloud Storage Manager provides you with further insights in to your Azure consumption. Providing you with quick to see capacity information, searching through all your Blob Storage, as well as historical reporting of your Azure Storage Accounts consumption.

If you want to see exactly what is in your Azure Storage Accounts, download Cloud Storage Manager and test it for yourself for free.

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