AZ-104 Question 149
Single answerYou are running a three-tier application on three Linux virtual machines in the West Europe region. The application must remain available even if an entire Azure datacenter becomes unavailable, and you also want to minimize downtime during planned maintenance events. How should you deploy these virtual machines to meet both requirements?
- A
Deploy all three VMs in a single availability set with two fault domains and one update domain
- B
Deploy all three VMs in the same availability zone
- C
Deploy each VM in a separate availability zone
- D
Deploy all three VMs in an availability set with three fault domains
Show answer and explanation
Correct answer: C
Explanation
By placing each virtual machine in its own availability zone, you achieve higher resiliency against datacenter-level outages within the region and still benefit from Azure’s capability to minimize downtime during planned maintenance events in each zone.
- A. Incorrect.
Placing all VMs in one availability set does not protect against a complete datacenter outage, as an availability set is confined to a single datacenter.
- B. Incorrect.
Running all VMs in the same availability zone does not protect against zone-level failures, which could bring all VMs offline in the event of a datacenter outage in that zone.
- C. Correct.
Distributing each VM to a separate availability zone ensures that a failure in any single zone does not bring all VMs offline, and leverages Azure’s zonal architecture for both high availability and minimized maintenance downtime.
- D. Incorrect.
Deploying the VMs in an availability set with three fault domains provides some hardware redundancy within one datacenter but does not protect the entire application if that datacenter fails.