AZ-305 Question 94
Single answerYou are designing a highly available media archive solution in Azure Blob Storage. The archive must remain available even if the primary Azure region experiences a major outage, and it must allow read-only access to the archived data from the secondary region without requiring a manual failover. Which Azure Storage redundancy option best meets these requirements?
- A
Locally Redundant Storage (LRS)
- B
Geo-Redundant Storage (GRS)
- C
Read-Access Geo-Redundant Storage (RA-GRS)
- D
Read-Access Geo-Zone Redundant Storage (RA-GZRS)
Show answer and explanation
Correct answer: D
Explanation
RA-GZRS combines zone-redundant storage in the primary region for high durability against zonal failures with geo-redundant replication. It also allows read access from the secondary region without manual failover, ensuring continuous data availability if the primary region is unavailable. Refer to Microsoft Azure documentation on storage redundancy (https://learn.microsoft.com/azure/storage/common/storage-redundancy) for more details on selecting the most appropriate redundancy option.
- A. Incorrect.
Option 1 (LRS): This stores multiple copies of your data within a single datacenter in one Azure region. While it ensures durability within that datacenter, it does not protect against regional outages or allow read access from a secondary region, so it does not meet the requirement.
- B. Incorrect.
Option 2 (GRS): Geo-Redundant Storage replicates your data asynchronously to a secondary region for disaster recovery. However, it does not provide immediate read access to the secondary region without a failover, which must be triggered manually, so it does not fully satisfy the 'read-only access' requirement.
- C. Incorrect.
Option 3 (RA-GRS): Read-Access Geo-Redundant Storage replicates your data to a secondary region and allows read access from that secondary region for workloads, even if the primary region remains online. However, it does not add zone-level redundancy within the primary region, which can be crucial for additional durability in zonal failures.
- D. Correct.
Option 4 (RA-GZRS): Read-Access Geo-Zone Redundant Storage provides both zone-level redundancy in the primary region and asynchronous replication to another geographically separate region. It also allows read access from the secondary region at any time, without a manual failover. This option best meets the scenario requirements.