A company needs to store backup data that must be retained for 7 years. They want to store the data as cheaply as possible, and access may be rare. Which Azure Storage access tier is most cost-effective?
Archive tier offers the lowest storage cost for data that is accessed rarely, with retrieval taking hours.
Why this answer
The Archive tier is the most cost-effective option for data that must be retained for 7 years with rare access. It offers the lowest storage cost among Azure Blob Storage access tiers, specifically designed for long-term retention where retrieval latency of up to 15 hours is acceptable. This aligns perfectly with the requirement to minimize cost while meeting the 7-year retention period.
Exam trap
The trap here is that candidates often confuse 'cheapest storage cost' with 'cheapest overall cost,' overlooking the high retrieval costs and rehydration latency of the Archive tier, or they mistakenly choose Cool tier because it sounds 'cool enough' for rare access without considering the 7-year retention requirement.
How to eliminate wrong answers
Option A is wrong because the Hot tier is optimized for frequent access (e.g., multiple times per day) and has higher storage costs than Cool or Archive tiers, making it unsuitable for rarely accessed backup data. Option B is wrong because the Cool tier, while cheaper than Hot, is designed for data accessed infrequently (e.g., once every 30 days) and still incurs higher storage costs than Archive, plus early deletion penalties if data is deleted before 30 days. Option D is wrong because the Premium tier is intended for low-latency, high-performance workloads (e.g., Azure Virtual Machine disks) and has the highest storage cost, making it completely inappropriate for cheap, long-term backup storage.