AZ-104 Practice Question 4: Storage Redundancy Selection
Microsoft Azure Administrator Associate (AZ-104) · Test 1 · question 4 of 10
You are creating a general-purpose v2 storage account in a region that supports availability zones. The application team gives you two requirements:
- Writes must keep succeeding if a single availability zone in the primary region fails. - During a full outage of the primary region, the application must still be able to read the data without waiting for an administrator to trigger a failover.
Which redundancy option should you select?
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Answer:
RA-GZRS is the only option that satisfies both requirements. GZRS writes data synchronously across three or more availability zones in the primary region, so a single zone failure does not stop reads or writes, and it then replicates asynchronously to the paired secondary region. The RA- prefix is what makes the secondary endpoint (<account>-secondary.blob.core.windows.net) readable at any time, including during a primary-region outage, with no failover step.
Option B, ZRS, covers the zone requirement but keeps all copies in the primary region. A regional outage would leave the data unreadable.
Option C, GRS, protects against a regional disaster but replicates within the primary region using LRS, a single datacenter, so a zone failure can take the account offline. GRS also leaves the secondary inaccessible for reads unless you perform an account failover.
Option D, RA-GRS, gives read access to the secondary but, like GRS, uses LRS in the primary region and therefore fails the availability-zone requirement.
Reference: Azure Storage redundancy