- A
An availability set
Why wrong: Availability sets improve resiliency but do not autoscale.
- B
A Virtual Machine Scale Set
Scale Sets provide grouped deployment and autoscaling.
- C
A Recovery Services vault
Why wrong: Recovery Services vaults are for backup and recovery.
- D
Boot diagnostics
Why wrong: Boot diagnostics is for troubleshooting and not VM fleet scaling.
Question 939 of 1,170
VMSS Autoscaling Based on CPU Demand
This AZ-104 practice question tests your understanding of deploy and manage azure compute. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
You need to deploy 30 identical Azure virtual machines for a web application and scale the instance count automatically based on CPU demand. Which Azure compute feature should you use?
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
✓
A Virtual Machine Scale Set
Virtual Machine Scale Sets (VMSS) are designed specifically to deploy and manage a group of identical, load-balanced VMs that can automatically scale in or out based on CPU demand or other metrics. This matches the requirement for 30 identical VMs and autoscaling, making B the correct choice.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
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
Why it's wrong here
Availability sets improve resiliency but do not autoscale.
When this WOULD be correct
You need to ensure that two or more VMs hosting a critical application remain available during planned maintenance or hardware failures, without automatic scaling requirements.
- ✓
A Virtual Machine Scale Set
Why this is correct
Scale Sets provide grouped deployment and autoscaling.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
A Recovery Services vault
Why it's wrong here
Recovery Services vaults are for backup and recovery.
When this WOULD be correct
A question asking how to protect Azure virtual machines by enabling backup and restore capabilities, or how to implement site recovery for failover, would have Recovery Services vault as the correct answer.
- ✗
Boot diagnostics
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.
✓A Virtual Machine Scale SetCorrect answer▾
Why this is correct
Scale Sets provide grouped deployment and autoscaling.
✗An availability setWrong answer — click to see why▾
Why this is wrong here
An availability set provides high availability by distributing VMs across fault and update domains, but it does not support automatic scaling based on CPU demand.
★ When this WOULD be the correct answer
You need to ensure that two or more VMs hosting a critical application remain available during planned maintenance or hardware failures, without automatic scaling requirements.
Why candidates choose this
Candidates may confuse availability sets with scale sets, thinking both provide scaling capabilities, or they may focus on the 'deploy 30 identical VMs' part and overlook the scaling requirement.
✗A Recovery Services vaultWrong answer — click to see why▾
Why this is wrong here
A Recovery Services vault is used for backup and disaster recovery, not for deploying or scaling virtual machines. It does not provide automatic scaling based on CPU demand.
★ When this WOULD be the correct answer
A question asking how to protect Azure virtual machines by enabling backup and restore capabilities, or how to implement site recovery for failover, would have Recovery Services vault as the correct answer.
Why candidates choose this
Candidates may confuse 'Recovery' with 'scaling' or think it provides some form of resilience that includes scaling, but it is solely for backup and disaster recovery.
✗Boot diagnosticsWrong answer — click to see why▾
Why this is wrong here
Boot diagnostics provides troubleshooting information for VM boot failures, but it does not support deploying multiple VMs or autoscaling based on CPU demand.
★ When this WOULD be the correct answer
You need to enable serial console access or collect boot logs to diagnose why a specific Azure VM is failing to start. Boot diagnostics would be the correct feature to use.
Why candidates choose this
Candidates may confuse boot diagnostics with a feature that helps manage VM performance or scaling, or they might think it's related to initial deployment configuration.
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?”
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse availability sets (which provide high availability) with scale sets (which provide both high availability and autoscaling), leading them to pick A when the question explicitly requires automatic scaling based on demand.
Detailed technical explanation
How to think about this question
VMSS uses a scale-in and scale-out policy based on autoscale rules, which can be triggered by metrics like CPU percentage (e.g., >75% for 5 minutes triggers scale-out). Under the hood, VMSS leverages Azure Resource Manager templates and can integrate with Azure Load Balancer or Application Gateway for traffic distribution. A real-world scenario: a retail web app using VMSS to handle Black Friday traffic spikes by automatically adding instances when CPU exceeds 80% and removing them when it drops below 30%.
KKey Concepts to Remember
- Read the scenario before looking for a memorised answer.
- Find the constraint that changes the correct option.
- Eliminate answers that are true in general but not in this case.
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
An e-commerce site experiences heavy traffic on Black Friday and near-zero traffic during off-peak weeks. Rather than provisioning permanent large VMs, the team uses auto-scaling groups that add capacity automatically under load and reduce it overnight. Questions like this test whether you understand elasticity, availability zones, and cloud compute scaling patterns.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
- →
Deploy and Manage Azure Compute — study guide chapter
Learn the concepts, then practise the questions
- →
Deploy and Manage Azure Compute practice questions
Targeted practice on this topic area only
- →
All AZ-104 questions
1,170 questions across all exam domains
- →
AZ-104 study guide
Full concept coverage aligned to exam objectives
- →
AZ-104 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related AZ-104 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Manage Azure Identities and Governance practice questions
Practise AZ-104 questions linked to Manage Azure Identities and Governance.
Implement and Manage Storage practice questions
Practise AZ-104 questions linked to Implement and Manage Storage.
Deploy and Manage Azure Compute practice questions
Practise AZ-104 questions linked to Deploy and Manage Azure Compute.
Implement and Manage Virtual Networking practice questions
Practise AZ-104 questions linked to Implement and Manage Virtual Networking.
Monitor and Maintain Azure Resources practice questions
Practise AZ-104 questions linked to Monitor and Maintain Azure Resources.
AZ-104 Azure RBAC practice questions
Practise AZ-104 questions linked to AZ-104 Azure RBAC.
AZ-104 storage account practice questions
Practise AZ-104 questions linked to AZ-104 storage account.
AZ-104 virtual network practice questions
Practise AZ-104 questions linked to AZ-104 virtual network.
AZ-104 NSG practice questions
Practise AZ-104 questions linked to AZ-104 NSG.
AZ-104 Azure Monitor practice questions
Practise AZ-104 questions linked to AZ-104 Azure Monitor.
AZ-104 backup practice questions
Practise AZ-104 questions linked to AZ-104 backup.
AZ-104 managed identity practice questions
Practise AZ-104 questions linked to AZ-104 managed identity.
Practice this exam
Start a free AZ-104 practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this AZ-104 question test?
Deploy and Manage Azure Compute — This question tests Deploy and Manage Azure Compute — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: A Virtual Machine Scale Set — Virtual Machine Scale Sets (VMSS) are designed specifically to deploy and manage a group of identical, load-balanced VMs that can automatically scale in or out based on CPU demand or other metrics. This matches the requirement for 30 identical VMs and autoscaling, making B the correct choice.
What should I do if I get this AZ-104 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Same concept, more angles
2 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 stateless web application must automatically add VM instances during business hours and remove them at night based on CPU usage. Which Azure service should be deployed?
easy- ✓ A.Virtual machine scale set
- B.Availability set
- C.Azure Bastion
- D.Proximity placement group
Why A: Virtual Machine Scale Sets (VMSS) are designed to automatically scale the number of VM instances in or out based on metrics like CPU usage, and they support scheduled scaling to align with business hours. This makes them the correct choice for a stateless web application that needs to add instances during business hours and remove them at night, as VMSS can integrate with Azure Autoscale to adjust capacity based on both performance metrics and time schedules.
Variation 2. You need to deploy 25 identical Azure virtual machines for a web application and scale the number of instances automatically based on CPU demand. Which Azure compute feature should you use?
medium- A.An availability set
- ✓ B.A Virtual Machine Scale Set
- C.A Recovery Services vault
- D.Boot diagnostics
Why B: A Virtual Machine Scale Set (VMSS) is the correct Azure compute feature because it allows you to deploy and manage a group of identical, load-balanced VMs whose number can automatically increase or decrease in response to CPU demand using autoscale rules. This directly meets the requirement for 25 identical VMs with automatic scaling based on CPU metrics.
Keep practising
More AZ-104 practice questions
- A storage automation service principal must upload, read, and delete blob data in one container by using Microsoft Entra…
- A subnet contains several application servers. You need to allow inbound TCP 3389 only from a management subnet named Su…
- A subscription admin wants to investigate who changed a resource and also review the platform-generated events for that…
- Based on the exhibit, which Azure feature should the administrator use to track this kind of platform-wide service issue…
- An administrator wants a script running on an Azure VM to create a resource in Azure without storing any passwords or cl…
- A PowerShell script runs on an Azure VM every night and uses Azure CLI commands to create tags and VM resources in anoth…
Last reviewed: Jun 11, 2026
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.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.