Which storage tier should you use?

A

Data in the cool access tier can tolerate slightly lower availability, but still requires high durability, retrieval latency, and throughput characteristics similar to hot data. For cool data, a slightly lower availability service-level agreement (SLA) and higher access costs compared to hot data are acceptable trade-offs for lower storage costs.

Incorrect Answers:

B: Archive storage stores data offline and offers the lowest storage costs but also the highest data rehydrate and access costs.

Archive - Optimized for storing data that is rarely accessed and stored for at least 180 days with flexible latency requirements (on the order of hours).

https://docs.microsoft.com/en-us/azure/storage/blobs/storage-blob-storage-tiers

For the given scenario, where the data in Azure Blob storage needs to be stored for many years and will be accessed rarely, and needs to ensure that the data is always available for immediate access and minimize storage costs, the recommended storage tier to use is the "Archive" tier.

Here's a detailed explanation of why Archive tier is the best fit for this scenario:

• Azure Blob Storage has three storage tiers available: Hot, Cool, and Archive.
• The Hot tier is intended for frequently accessed data and has the highest storage costs compared to the other tiers.
• The Cool tier is for infrequently accessed data and offers lower storage costs compared to the Hot tier, but with slightly higher access costs.
• The Archive tier is intended for rarely accessed data, with the lowest storage costs but the highest access costs.
• When data is stored in the Archive tier, it is not immediately available for access, but requires a restore process, which can take several hours.
• The Archive tier offers a lower storage cost per GB compared to the other tiers, which makes it the best fit for storing data that is accessed rarely and needs to be stored for a long period, while minimizing storage costs.
• Although the Archive tier has higher access costs, if the data is only accessed rarely, the overall cost is still lower compared to the other tiers.

To summarize, the Archive tier is the best fit for storing data that is accessed rarely, and needs to be stored for a long period, while minimizing storage costs. The Hot and Cool tiers are more suitable for frequently accessed data, where the priority is immediate availability over storage costs.