AZ-104 Deploy and Manage Azure Compute Practice Question
A stateless web app runs on two Ubuntu VMs behind an Azure Load Balancer. The region supports availability zones. The business wants the app to survive a full datacenter outage and also avoid having both VMs on the same maintenance boundary. Which deployment should you choose?
⚠ Common exam trap
It's easy for candidates to confuse availability sets (which protect within a datacenter) with availability zones (which protect across datacenters), and fail to recognize that only zones can survive a full datacenter outage while also avoiding shared maintenance boundaries.
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
✓
Place the VMs in separate availability zones in the same region.
Deploying the VMs in separate availability zones ensures they are placed in physically distinct datacenters within the same region, protecting against a full datacenter outage. Additionally, each availability zone has its own fault and update domains, so the VMs will never share the same maintenance boundary, meeting both business requirements.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Place both VMs in a single availability set.
Why it's wrong here
An availability set improves resilience against rack-level failures and planned maintenance by placing VMs in different fault domains and update domains, but all of those domains still live within a single Azure datacenter. A full datacenter outage -- for example, loss of power, cooling, or upstream connectivity to that facility -- will bring down every fault domain in the set, including both of your VMs. For a stateless web app that must stay online, you need isolation at the zone level, where zones are physically separate datacenters, rather than only rack-level separation. Since the load balancer already fronts the VMs, distributing them across availability zones is a stronger design.
When this WOULD be correct
A question that asks for high availability within a single datacenter (e.g., 'survive a server rack failure') without requiring multi-datacenter resilience, and the region does not support availability zones.
- ✗
Deploy one VM and rely on Azure Backup for recovery.
Why it's wrong here
Backup is designed for disaster recovery, not for ongoing availability. If the single VM fails, Azure Backup can restore its VHD or files to a new VM, but that process requires manual or scripted actions and can take minutes to hours. During that time the application is offline, and because the load balancer has only one back-end VM, it has no healthy target to route traffic to. Additionally, the most recent backup only covers the configured RPO, so you could lose any changes made after the last backup.
When this WOULD be correct
If the question asked for a cost-effective disaster recovery solution for a non-critical app where some downtime is acceptable, and the business wants to recover data after a regional failure, then deploying one VM with Azure Backup would be correct.
- ✓
Place the VMs in separate availability zones in the same region.
Why this is correct
Availability zones place workloads in physically separate datacenters within the same region. That design protects against a full zone or datacenter outage and also gives you a stronger isolation boundary than an availability set. Because the app has two VMs behind a load balancer, you can distribute them across zones and maintain service if one zone becomes unavailable.
- ✗
Deploy both VMs without any fault-domain configuration.
Why it's wrong here
When you deploy two VMs without any fault-domain or availability-zone configuration, Azure offers no guarantee about their physical placement. In the worst case, they can be placed on the same host server or the same rack, so a single hardware failure, a firmware update, or a top-of-rack switch outage brings down both instances simultaneously. You also get no protection from simultaneous patching, because Azure can apply the same update-domain event to both VMs together. This negates the value of running two VMs behind a load balancer and is strictly less resilient than using either an availability set or availability zones.
When this WOULD be correct
This option would be correct in a scenario where the application is not critical, cost is the primary constraint, and the business accepts the risk of downtime during maintenance or failures, such as for a development or test environment.
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.
✓Place the VMs in separate availability zones in the same region.Correct answer▾
Why this is correct
Availability zones place workloads in physically separate datacenters within the same region. That design protects against a full zone or datacenter outage and also gives you a stronger isolation boundary than an availability set. Because the app has two VMs behind a load balancer, you can distribute them across zones and maintain service if one zone becomes unavailable.
✗Place both VMs in a single availability set.Wrong answer — click to see why▾
Why this is wrong here
An availability set protects against rack-level failures within a single datacenter, not a full datacenter outage. The requirement to survive a full datacenter outage demands availability zones, which span separate physical locations.
★ When this WOULD be the correct answer
A question that asks for high availability within a single datacenter (e.g., 'survive a server rack failure') without requiring multi-datacenter resilience, and the region does not support availability zones.
Why candidates choose this
Candidates often confuse availability sets with availability zones, thinking both provide similar disaster recovery capabilities, or they underestimate the scope of a 'full datacenter outage'.
✗Deploy one VM and rely on Azure Backup for recovery.Wrong answer — click to see why▾
Why this is wrong here
Azure Backup provides disaster recovery for data and VMs, but it does not ensure high availability or prevent downtime during a datacenter outage; recovery takes time and the app would be unavailable.
★ When this WOULD be the correct answer
If the question asked for a cost-effective disaster recovery solution for a non-critical app where some downtime is acceptable, and the business wants to recover data after a regional failure, then deploying one VM with Azure Backup would be correct.
Why candidates choose this
Candidates may confuse disaster recovery (Backup) with high availability, thinking that backup can quickly restore the app in another location, but fail to consider the recovery time and lack of automatic failover.
✗Deploy both VMs without any fault-domain configuration.Wrong answer — click to see why▾
Why this is wrong here
Deploying both VMs without fault-domain configuration does not protect against a full datacenter outage or maintenance events, as both VMs could be placed on the same physical host or within the same datacenter, violating the requirement for high availability.
★ When this WOULD be the correct answer
This option would be correct in a scenario where the application is not critical, cost is the primary constraint, and the business accepts the risk of downtime during maintenance or failures, such as for a development or test environment.
Why candidates choose this
Candidates may think that simply deploying VMs without any configuration is sufficient for basic availability, or they may overlook the need for explicit fault-domain placement to meet high-availability requirements.
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 zone
An Availability Zone is a distinct, isolated location within a cloud region that contains its own power, cooling, and networking, designed to protect applications from single points of failure.
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
3 more ways 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 web tier consists of two Azure VMs in a region that supports availability zones. The business requirement is to survive a full datacenter outage in that region without deploying to a second region. What should the administrator use?
hard- A.An availability set with multiple update domains
- ✓ B.Availability zones with the VMs placed in different zones
- C.A proximity placement group for both VMs
- D.A single-zone virtual machine scale set
Why B: Availability zones are physically separate datacenters within an Azure region, each with independent power, cooling, and networking. Placing the two VMs in different zones ensures that if one entire datacenter fails, the other VM remains operational, meeting the requirement to survive a full datacenter outage without deploying to a second region.
Variation 2. A company runs two identical Linux VMs for a stateless web app in an Azure region that supports availability zones. The business requires protection from a full datacenter outage, not just planned host maintenance. Which deployment choice best meets this requirement?
medium- A.Place both VMs in an availability set.
- ✓ B.Deploy the VMs across availability zones.
- C.Use a proximity placement group for both VMs.
- D.Deploy both VMs in a single-zone virtual machine scale set.
Why B: Deploying the two VMs across different availability zones ensures that each VM resides in a physically separate datacenter within the region. This architecture protects against a full datacenter outage, as an availability zone failure affects only one zone, leaving the other VM operational. Availability zones provide a 99.99% SLA for VMs when two or more instances are deployed across zones, which aligns with the requirement for protection beyond planned host maintenance.
Variation 3. A business wants a line-of-business VM workload to keep running if one Azure datacenter in the region goes offline. Which two deployment choices should the administrator use? Select two.
easy- ✓ A.Deploy the VMs in different availability zones.
- B.Place the VMs in the same availability set.
- ✓ C.Choose an Azure region that supports availability zones.
- D.Use a proximity placement group for the VMs.
- E.Use a snapshot of the operating system disk.
Why A: Deploying VMs across different availability zones protects against a single datacenter failure. Each availability zone is a physically separate datacenter within an Azure region, with independent power, cooling, and networking. If one zone goes offline, the VM in the other zone remains operational, ensuring business continuity for the line-of-business workload.
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.