Getting Started With Cool Blob Storage Service In Azure

Recent additions to azure services introduced cool blob storage service,  and as you have landed here that means you are either interested in knowing more about Azure cool blob storage service or you have heard about it recently somewhere.

There is no second opinion to the fact that all azure offerings are very ‘cool;'  however, don’t get yourself confused with ‘cool’ blob as some funky blob J. Jokes aside – Microsoft Azure has introduced a new way of storing your data in blob storage offering you economic benefits, let’s see it in detail.


With the huge adoption of Azure by various enterprises at a high rate, the amount of data getting stored in azure storage is exponentially increasing and teams at Microsoft are always looking out for options to help you with better management and cost of this data.

Until today, as a part of Azure storage account services, consumers used to get access to the below set of services

  • Blob Storage - Block blobs and Page blobs
  • Storage queues
  • Table storage
  • File services

Out of which we will take close look a tthe blob storage offering. It is the offering which lets you put any type of data in azure storage and it gets saved as chunks of bits. Again, while saving data in blob – you have two options i.e. save as block blob or as page blob.

Block blob option is something which is recommended by Microsoft unless the data you have has specific requirements of page blobs.

Let’s say – we are designing a solution wher in all of the log files will be stored in azure storage as block blobs. Sounds easy and straightforward doesn’t it – and you are right it is a quite simple task and can be achieved easily with the help of storage providers but let’s think of it in the cost angle.

The cost perspective

In typical enterprise systems – no one really cares about the generated log files unless you get any support ticket which might need a deep level of troubleshooting including analysis of log files, until then files will be just dumped, rarely accessed in the storage.

Cool blobs

Well, to reduce such cost – Azure has now unleashed a new concept of blob tiers; i.e., Hot and Cold blob tiers.

Cool blob tier can be utilized for a scenario which we just saw and is an ideal choice where data in storage is passively accessed, however on the other side the hot tier offering is for scenarios where data is frequently accessed, modified and needs to be highly available and durable.

Cool data can support slightly lower availability than hot data but requires high durability.

Now with the offering of cool and hot tiers of azure blob storage you can choose to store less frequently accessed data (cool data) in cool tier with lower storage cost and frequently accessed data in hot tier with lower access cost.

We can summarize the above in short table as below


Storage Cost

Access Cost

Cool Data



Hot Data



Let’s see it with real cost mentioned here.

To avoid redundancy of content – I will copy data only for LRS from the URL above with INR pricing (values below as copied from URL above as of writing this article and may change in future)

Access cost shown is for Put Blob/Block, List, and Create Container Operations


Storage Cost (100 TBs / Month)

Access Cost (per 10000)

Cool Data

Rs. 0.96/-

Rs 6.01/-

Hot Data

Rs 1.44/-

Rs 3.00/-

Blob storage account is compatible with existing blob storage APIs and performs similarly in terms of latency and throughput and supports same scalability and security features, however it offers slightly lower availability of 99% compared to 99.9% availability of regular storage account.

Though it is encouraged to use blob storage account and leverage different pricing tiers for storing data, however there might be certain scenarios where in you might need to go with the standard typical option of general purpose storage account, some of such scenarios can be

  • You need storage account created though class deployment
  • You need to use other services of storage account such as table storage, storage queues and file with single access key
  • Requirement of page blobs
  • Need to access blobs with storage APIs earlier version than 4.0

Note that currently, blob storage offerings with these hot and cool tiers is available only for storage accounts created though ARM mode.

As of writing this, there are certain regions in which cold blob storage service is not yet available but as per Microsoft it should be available soon, you can check services and their availability in various regions here.

Here is how both can be visualized


Let’s see it in action using Azure portal

Log in to the azure Portal and click on +New icon located at top left corner of the dashboard.

Search for storage account in filter box and click on storage account option to create a new storage account.

Click on create and you will be presented with typical storage account creation screen

Note that there is a new option to specify account kind now available wherein you can select which type of storage account you want to create i.e. General Purpose or Blob storage.

Also observe that deployment mode selected is Resource manager, if you select classic deployment mode then account kind will be set to general purpose and will be read only.

If you continue to go with blob storage kind, you will be shown option to specify which type of blob storage account you want to create i.e. cold or hot. We will select cold and continue with creation.

Once it is created, let’s see how it looks and we will start from dashboard

Note that exact same set of settings is available as compared to general purpose storage account except it doesn’t list services on the dashboard.

We will add the storage account in Azure storage explorer to see what all offerings it lists

Note that storage explored is showing queues and tables as available offerings but it seems there is some issue with storage explorer since it is not an up to date build considering latest release of cold blob storage service so you can ignore it, if you want you can try to create queues and tables in it and it throws an exception which is expected.

All of the other basic storage account actions like uploading blob, downloading blob and deleting blob with the help of storage APIs remain the same and this article won’t be repeating the same content which is already very well documented here.

Thanks for reading this article and I hope it helped you to understand the concept of cold blob storage.

Feel free to post your views and comments.

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