AZ-305 Question 92
Single answerA global retail company stores large amounts of mission-critical data in Azure Storage. They need to ensure that their data remains accessible even in case of a complete regional outage. Additionally, they want to enable read operations from a secondary region if the primary location is unavailable, without requiring a manual failover. Which storage replication approach should you recommend to meet these requirements for protection and durability?
- A
Locally Redundant Storage (LRS)
- B
Geo-Redundant Storage (GRS)
- C
Read-Access Geo-Redundant Storage (RA-GRS)
- D
Zone-Redundant Storage (ZRS)
Show answer and explanation
Correct answer: C
Explanation
Read-Access Geo-Redundant Storage (RA-GRS) provides a secondary replica of data in another region and allows read access to that replica immediately, meeting high-availability needs and offering additional durability for mission-critical data. According to Microsoft’s documentation on Azure Storage redundancy, RA-GRS is ideal for scenarios where you require region-level protection and the ability to read from the secondary location if the primary region is inaccessible.
- A. Incorrect.
Option 1: Locally Redundant Storage (LRS) only keeps three copies within a single data center in the same region. If that entire region becomes unavailable, data access is lost. Therefore, this option does not meet the requirement for regional outage protection.
- B. Incorrect.
Option 2: Geo-Redundant Storage (GRS) stores copies in a secondary region, but read access to the secondary region is not enabled by default. During an outage of the primary region, you would have to initiate a manual failover to access the data in the secondary region, which doesn’t fulfill the requirement for continuous read access.
- C. Correct.
Option 3: Read-Access Geo-Redundant Storage (RA-GRS) builds on GRS by allowing read access from the secondary region immediately, without the need for a manual failover. It meets the requirement for continuous data availability and protection against regional outages.
- D. Incorrect.
Option 4: Zone-Redundant Storage (ZRS) replicates data across different availability zones within the same region. While this protects against a zonal outage, it does not protect against a full regional outage. It also does not provide read access from a secondary region.