AZ-104 Deploy and Manage Azure Compute Practice Question
You need to deploy a set of identical Azure virtual machines that can automatically scale out during demand spikes and scale in when usage falls. Which Azure feature should you use?
⚠ Common exam trap
Candidates often confuse an availability set (which provides high availability) with a scale set (which provides both high availability and automatic scaling), leading them to pick Option A when the question explicitly asks for automatic scaling.
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
A Virtual Machine Scale Set (VMSS) is the correct Azure feature because it is designed specifically to deploy and manage a set of identical, load-balanced VMs that can automatically scale out (increase instance count) during demand spikes and scale in (decrease instance count) when usage falls, using autoscale rules based on metrics like CPU or memory.
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 resilience but do not provide autoscaling.
When this WOULD be correct
You need to ensure that two or more VMs remain available during planned maintenance or unplanned failures. An availability set would be the correct answer for a question about high availability, not autoscaling.
- ✓
A Virtual Machine Scale Set
Why this is correct
Scale Sets provide fleet management and autoscaling for identical VMs.
- ✗
A Recovery Services vault
Why it's wrong here
A Recovery Services vault is for backup and recovery.
When this WOULD be correct
You need to protect a set of Azure VMs by enabling backup and restore capabilities. Which Azure resource should you create?
- ✗
Boot diagnostics
Why it's wrong here
Boot diagnostics is for troubleshooting VM startup issues.
When this WOULD be correct
A question asks: 'You need to troubleshoot why an Azure VM is not booting properly. Which feature should you enable to capture console output and screenshots?' Boot diagnostics would be the correct answer.
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 fleet management and autoscaling for identical VMs.
✗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 demand.
★ When this WOULD be the correct answer
You need to ensure that two or more VMs remain available during planned maintenance or unplanned failures. An availability set would be the correct answer for a question about high availability, not autoscaling.
Why candidates choose this
Candidates may confuse availability sets with scale sets because both involve multiple VMs, and they might think availability sets also handle scaling, but they only provide redundancy.
✗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 (Azure Backup / Site Recovery), not for automatic scaling of virtual machines.
★ When this WOULD be the correct answer
You need to protect a set of Azure VMs by enabling backup and restore capabilities. Which Azure resource should you create?
Why candidates choose this
Candidates may confuse 'Recovery' with 'resilience' or 'scaling' because both involve handling failures or load changes, but the vault is for data protection, not compute scaling.
✗Boot diagnosticsWrong answer — click to see why▾
Why this is wrong here
Boot diagnostics captures serial logs and screenshots for troubleshooting VM boot failures, but it does not provide any auto-scaling capabilities to handle demand spikes or scale-in.
★ When this WOULD be the correct answer
A question asks: 'You need to troubleshoot why an Azure VM is not booting properly. Which feature should you enable to capture console output and screenshots?' Boot diagnostics would be the correct answer.
Why candidates choose this
Candidates may confuse boot diagnostics with a monitoring or scaling tool because it involves logging and diagnostics, leading them to think it could help with scaling decisions.
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?”
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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.