You plan to store data in Azure Blob storage for many years. The stored data will be accessed rarely.
You need to ensure that the data in Blob storage is always available for immediate access. The solution must minimize storage costs.
Which storage tier should you use?
Azure cool tier is equivalent to the Amazon S3 Infrequent Access (S3-IA) storage in AWS that provides a low cost high performance storage for infrequently access data.
Note: Azure's cool storage tier, also known as Azure cool Blob storage, is for infrequently-accessed data that needs to be stored for a minimum of 30 days.
Typical use cases include backing up data before tiering to archival systems, legal data, media files, system audit information, datasets used for big data analysis and more.
The storage cost for this Azure cold storage tier is lower than that of hot storage tier. Since it is expected that the data stored in this tier will be accessed less frequently, the data access charges are high when compared to hot tier. There are no additional changes required in your applications as these tiers can be accessed using APIs in the same manner that you access Azure storage.
Even though Azure archive storage offers the lowest cost in terms of data storage, its data retrieval charges are higher than that of hot and cool tiers. In fact, the data in the archive tier remains offline until the tier of the data is changed using a process called hydration. The process of hydrating data in the archive storage tier and moving it to either hot or cool tier could take up to 15 hours and, hence, it is only intended for data that can afford that kind of access delay.
The storage cost for this Azure cold storage tier is lower than that of hot storage tier.