Learn about Azure storage redundancy options like geo-redundant storage and read-only geo-redundant storage for configuring geo-clustered datacenters. Get a detailed answer and explanation to this sample Microsoft AZ-900 certification exam question.
Table of Contents
Question
Your company has datacenters in Los Angeles and New York. The company has a Microsoft Azure subscription.
You are configuring the two datacenters as geo-clustered sites for site resiliency.
You need to recommend an Azure storage redundancy option.
You have the following data storage requirements:
- Data must be stored on multiple nodes.
- Data must be stored on nodes in separate geographic locations.
- Data can be read from the secondary location as well as from the primary location
Which of the following Azure stored redundancy options should you recommend?
A. Geo-redundant storage
B. Read-only geo-redundant storage
C. Zone-redundant storage
D. Locally redundant storage
Answer
The correct Azure storage redundancy option to recommend based on the requirements is:
B. Read-only geo-redundant storage
Explanation
Read-only geo-redundant storage (RA-GRS) is the appropriate option because it meets all of the stated requirements:
- Data must be stored on multiple nodes: RA-GRS stores multiple copies of your data across two geographical regions, a primary and secondary region. Within each region, data is replicated synchronously three times across separate fault domains and upgrade domains. This ensures data is stored on multiple nodes.
- Data must be stored on nodes in separate geographic locations: With RA-GRS, data is first replicated from the primary to secondary region asynchronously. The secondary region is typically hundreds of miles away from the primary region, providing geographic redundancy.
- Data can be read from the secondary location as well as the primary location: The key difference between GRS and RA-GRS is that RA-GRS provides a read-only endpoint for the secondary region. This allows you to read data from the secondary if the primary becomes unavailable. With regular GRS, the secondary is not accessible until Microsoft initiates a failover.
The other options are incorrect because:
A. Geo-redundant storage (GRS) does not allow read access from the secondary location. You would need to wait for Microsoft to failover to the secondary before being able to read data.
C. Zone-redundant storage (ZRS) only replicates data across availability zones within a single region. It does not provide redundancy across separate geographic locations.
D. Locally redundant storage (LRS) only replicates data within a single datacenter in the primary region. It does not provide any geo-redundancy.
Therefore, read-only geo-redundant storage (RA-GRS) is the best option to meet the specified resiliency and accessibility requirements for the geo-clustered datacenters.
Microsoft AZ-900 certification exam practice question and answer (Q&A) dump with detail explanation and reference available free, helpful to pass the Microsoft AZ-900 exam and earn Microsoft AZ-900 certification.