AZ-104 Deploy and Manage Azure Compute Practice Question
You plan to run a web application on Azure virtual machines and need protection against a single datacenter failure within an Azure region. Which deployment option should you use?
⚠ Common exam trap
Many candidates confuse availability sets (which protect against rack-level failures within one datacenter) with availability zones (which protect against full datacenter failures), leading them to select the cheaper or more familiar option without recognizing the critical difference in fault domain scope.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Availability zones
Availability Zones are physically separate datacenters within an Azure region, each with independent power, cooling, and networking. Deploying your VMs across two or more zones protects against a single datacenter failure because if one zone goes down, the application continues running in the other zone. This meets the requirement for datacenter-level fault tolerance within a single region.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
An availability set only
Why it's wrong here
An availability set protects against failures within a single datacenter by distributing VMs across multiple fault domains (hardware racks) and update domains. However, all VMs in an availability set still reside in the same datacenter, so a disaster that takes down the entire building—such as a fire, flood, or power grid failure—will take down every VM in the set. It does not match the datacenter-level isolation that availability zones provide.
When this WOULD be correct
If the question asked for protection against hardware failures within a single datacenter (e.g., server rack or maintenance events) and required high availability for IaaS VMs, an availability set would be the correct answer.
- ✓
Availability zones
Why this is correct
Availability zones are physically separate datacenters within an Azure region, each with independent power, cooling, and networking. Deploying VMs across zones isolates the workload from a single datacenter failure, so if one zone goes down the application remains available in the others. This is the only option listed that provides datacenter-level resilience.
- ✗
A proximity placement group
Why it's wrong here
A proximity placement group is designed to minimize network latency by ensuring VMs are physically close together, often within the same datacenter or even the same rack. This co-location concentrates failure domains, meaning a single datacenter or rack outage can affect all VMs in the group. It directly reduces resilience rather than improving it, so it is unsuitable for protecting against datacenter failure.
When this WOULD be correct
When the question asks for minimizing network latency between VMs in a tightly coupled workload (e.g., HPC or real-time data processing) within the same Azure region, a proximity placement group is the correct choice.
- ✗
A single VM with premium SSD
Why it's wrong here
A single VM with premium SSD, even with its high-performance managed disks that replicate data within a storage cluster, has no redundancy at the VM or datacenter level. The VM itself is a single point of failure—if the host hardware fails or the datacenter is disrupted, the application becomes unavailable despite the durable SSD. Premium SSDs improve storage performance and local durability but cannot protect against compute or infrastructure-wide outages.
When this WOULD be correct
This option would be correct for a question asking for the highest performance storage for a single VM running a latency-sensitive application, where data redundancy is handled at the application layer or via backups, not by Azure infrastructure.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The AZ-104 exam frequently reuses these exact scenarios with slightly different constraints.
✓Availability zonesCorrect answer▾
Why this is correct
Availability zones are physically separate datacenters within an Azure region, each with independent power, cooling, and networking. Deploying VMs across zones isolates the workload from a single datacenter failure, so if one zone goes down the application remains available in the others. This is the only option listed that provides datacenter-level resilience.
✗An availability set onlyWrong answer — click to see why▾
Why this is wrong here
An availability set protects against failures within a single datacenter (e.g., rack or update domain failures), not against a full datacenter failure within an Azure region. The question requires protection against a single datacenter failure, which spans across datacenters; availability zones are needed for that.
★ When this WOULD be the correct answer
If the question asked for protection against hardware failures within a single datacenter (e.g., server rack or maintenance events) and required high availability for IaaS VMs, an availability set would be the correct answer.
Why candidates choose this
Candidates often confuse availability sets with availability zones, thinking both provide similar datacenter-level redundancy, but availability sets only protect within one datacenter.
✗A proximity placement groupWrong answer — click to see why▾
Why this is wrong here
A proximity placement group reduces network latency between VMs but does not protect against a single datacenter failure; it may even place VMs in the same datacenter, increasing failure risk.
★ When this WOULD be the correct answer
When the question asks for minimizing network latency between VMs in a tightly coupled workload (e.g., HPC or real-time data processing) within the same Azure region, a proximity placement group is the correct choice.
Why candidates choose this
Candidates may confuse 'proximity' with 'redundancy' or think that grouping VMs together provides high availability, not realizing it focuses on low latency, not fault tolerance.
✗A single VM with premium SSDWrong answer — click to see why▾
Why this is wrong here
A single VM with premium SSD does not provide protection against a datacenter failure because it is a single instance; if the datacenter hosting that VM fails, the application becomes unavailable.
★ When this WOULD be the correct answer
This option would be correct for a question asking for the highest performance storage for a single VM running a latency-sensitive application, where data redundancy is handled at the application layer or via backups, not by Azure infrastructure.
Why candidates choose this
Candidates may think premium SSD offers high durability and performance, mistakenly believing it alone can protect against datacenter-level failures, confusing storage redundancy with availability guarantees.
Analysis generated from the official AZ-104blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Go deeper
Related to this question
Learn chapter
Managed Identities for Azure Resources
Key term
Region
A region is a distinct geographic location where a cloud provider operates multiple data centers that are connected by low-latency networks and provide cloud services.
Key term
Availability
Availability is the measure of how often a system or service is operational and accessible when needed, typically expressed as a percentage of uptime.
About these practice questions
This AZ-104 question is part of Courseiva's 1,049-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
Same concept, more angles
1 more way this is tested on AZ-104
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A line-of-business app requires protection against a datacenter outage in a region that supports zones. You want the strongest placement resilience available for the VMs. What should you choose?
easy- A.Availability set
- ✓ B.Availability zone
- C.Virtual machine scale set
- D.Resource lock
Why B: Availability zones are physically separate datacenters within an Azure region, each with independent power, cooling, and networking. Deploying VMs across zones provides the strongest resilience against a datacenter outage because if one zone fails, the other zones remain operational. This is the highest level of protection available within a single region for IaaS VMs.
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This AZ-104 practice question is part of Courseiva's free Microsoft certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the AZ-104 exam.