A company stores large amounts of log data in Azure Blob Storage. Logs are accessed frequently for the first 30 days, then rarely accessed afterward, but must be retained for 7 years for compliance. The company wants to minimize storage costs. They need to configure automatic data movement and retention policies. Which combination of Azure Blob Storage access tiers and lifecycle management policy should they use?
Trap 1: Use Hot tier for 30 days, then use Cool tier for 7 years, with a…
Using the Cool tier for a seven-year retention period overlooks that Archive tier provides a substantially lower storage price for data that is no longer actively accessed. While the lifecycle rule correctly automates deletion after 7 years, the Cool tier's storage rate is significantly higher than Archive for long-lived, rarely read data, making this solution unnecessarily expensive over the retention period. Since the data is only frequently accessed for the first 30 days, Cool tier is an economically suboptimal middle ground for the remaining 6+ years.
Trap 2: Use Cool tier for 30 days, then use Archive tier for 7 years, no…
Choosing Cool tier for the initial 30 days is cost-inefficient because Cool tier has higher per-GB read and retrieval costs than Hot tier, which already offers the lowest access costs for frequently used data. Additionally, without a lifecycle rule, the data will never be automatically deleted after 7 years, resulting in ongoing storage charges indefinitely. The correct pattern pairs a Hot tier for frequent reads with an Archive tier for infrequent, long-term retention, coupled with a lifecycle policy that deletes the blob at a specific age.
Trap 3: Use Archive tier immediately, with a lifecycle rule to delete after…
Placing data directly into Archive tier fails to account for the high frequency of access during the first 30 days; Archive tier's retrieval latency (typically minutes to hours) and per-GB read charges make it inappropriate for active use. Although the lifecycle rule handles the eventual deletion correctly, immediate archiving would force repeated expensive rehydration operations for the very data users need most often. A tiering strategy must match early access patterns with Hot tier, then transition to Archive only once the data becomes rarely accessed.
- A
Use Hot tier for 30 days, then use Cool tier for 7 years, with a lifecycle rule to delete after 7 years.
Why wrong: Using the Cool tier for a seven-year retention period overlooks that Archive tier provides a substantially lower storage price for data that is no longer actively accessed. While the lifecycle rule correctly automates deletion after 7 years, the Cool tier's storage rate is significantly higher than Archive for long-lived, rarely read data, making this solution unnecessarily expensive over the retention period. Since the data is only frequently accessed for the first 30 days, Cool tier is an economically suboptimal middle ground for the remaining 6+ years.
- B
Use Hot tier for 30 days, then use Archive tier for the remaining period, with a lifecycle rule to delete after 7 years.
Hot tier provides low-latency access during the frequent access period. Archive tier provides the lowest storage cost for data that is rarely accessed. A lifecycle policy can automatically move data from Hot to Archive after 30 days and delete it after 7 years.
- C
Use Cool tier for 30 days, then use Archive tier for 7 years, no lifecycle rule needed.
Why wrong: Choosing Cool tier for the initial 30 days is cost-inefficient because Cool tier has higher per-GB read and retrieval costs than Hot tier, which already offers the lowest access costs for frequently used data. Additionally, without a lifecycle rule, the data will never be automatically deleted after 7 years, resulting in ongoing storage charges indefinitely. The correct pattern pairs a Hot tier for frequent reads with an Archive tier for infrequent, long-term retention, coupled with a lifecycle policy that deletes the blob at a specific age.
- D
Use Archive tier immediately, with a lifecycle rule to delete after 7 years.
Why wrong: Placing data directly into Archive tier fails to account for the high frequency of access during the first 30 days; Archive tier's retrieval latency (typically minutes to hours) and per-GB read charges make it inappropriate for active use. Although the lifecycle rule handles the eventual deletion correctly, immediate archiving would force repeated expensive rehydration operations for the very data users need most often. A tiering strategy must match early access patterns with Hot tier, then transition to Archive only once the data becomes rarely accessed.