AZ-104 Deploy and Manage Azure Compute Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  Availability zones

  Why it's wrong here

  Availability zones protect against datacenter-level failure by distributing VMs across physically separate facilities within a region, but the requirement here is only to reduce downtime during planned host maintenance, not to survive a full datacenter outage. The correct solution—an availability set—uses fault domains and update domains to ensure VMs are on different physical hosts and are not updated simultaneously, directly addressing planned maintenance without the cost and complexity of zone-redundant architecture. This option is tempting because availability zones are the standard recommendation for high-availability scenarios requiring resilience against a complete datacenter loss, which would be the correct choice if that were the stated requirement.

  When this WOULD be correct

  This option would be correct if the question required protection from a complete datacenter outage (e.g., due to power failure or natural disaster) and the business needed high availability across physically separated facilities within the same region.

• ✓

  Availability set

  Why this is correct

  An availability set spreads VMs across update domains and fault domains within a datacenter boundary. That helps reduce downtime during planned maintenance and some hardware issues. Since the requirement does not include protection from an entire datacenter outage, an availability set is the right and simpler choice.

• ✗

  Virtual machine scale set

  Why it's wrong here

  A virtual machine scale set is an orchestration tool for deploying and automatically scaling a pool of identical VMs, typically to handle variable load. While a scale set can be configured with fault and update domain awareness, it is not the simplest solution for two application VMs whose primary requirement is resilience during planned maintenance. The requirement does not mention autoscaling or elasticity, and an availability set achieves the isolation needed with far less complexity and administrative overhead.

  When this WOULD be correct

  A question requiring automatic scaling of VMs based on demand, such as 'A company expects variable traffic to its web application and needs to automatically add or remove VM instances. Which option should you choose?'

• ✗

  Proximity placement group

  Why it's wrong here

  A proximity placement group is designed to reduce network latency by co-locating VMs in the same physical datacenter region, often within the same rack or cluster. This placement makes maintenance events like patching or hardware failures more likely to affect both VMs simultaneously because they share the same infrastructure. It does not introduce any isolation across update or fault domains, so it provides no protection against planned host maintenance and could actually increase correlated failure risk.

  When this WOULD be correct

  A question requiring the lowest network latency between VMs for a latency-sensitive application, such as high-performance computing or real-time data processing, where VMs must be physically close together.

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.

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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