AZ-104 Deploy and Manage Azure Compute Practice Question
You are deploying a new Windows VM and want it to start with the same custom software and configuration that already exist on an approved production VM. What should you use as the source for the new VM?
⚠ Common exam trap
Test-takers frequently confuse a snapshot with a custom image, not realizing that a snapshot is a disk-level backup requiring additional steps to create a deployable VM, whereas a custom image is directly usable for VM creation with the exact software and configuration.
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 custom image
A custom image captures the exact OS configuration, installed software, and settings from a source VM, allowing you to deploy new VMs with identical customizations. Unlike a marketplace image, which provides only a generic OS, a custom image preserves all modifications made to the approved production VM, including applications and system tweaks.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
A marketplace image
Why it's wrong here
A marketplace image serves as a standard starting point, offering preconfigured operating systems or software stacks from Microsoft and third-party publishers (e.g., Windows Server 2019, Ubuntu, or a database offer). However, it contains only the publisher's default configuration and does not include your organization's domain join settings, Line-of-Business (LOB) applications, custom security baselines, or other bespoke software. Relying solely on a marketplace image would require manually reconfiguring every new VM, defeating the goal of deploying consistently with the same baseline as the original VM.
When this WOULD be correct
When the question asks for deploying a VM using a standard, Microsoft-verified Windows Server image without any customizations, or when you need to quickly deploy a VM with common configurations and no requirement to replicate an existing VM's custom setup.
- ✓
A custom image
Why this is correct
A custom image is a generalized virtual hard disk (VHD) or managed image that contains the operating system, preinstalled software, and configuration settings (e.g., Windows updates, system roles, local policies) captured from a prepared source VM. For Windows, the source VM is generalized using Sysprep to remove machine-specific identifiers, making the image reusable for creating any number of identical VMs. Deploying from a custom image is the standard, supported way to launch new VMs with the exact same baseline and organizational configuration.
- ✗
A snapshot of the OS disk
Why it's wrong here
A snapshot is a read-only, point-in-time copy of a managed disk, typically used for backup, disaster recovery, or to create a new disk for a one-off recovery scenario. Although you could potentially create a VM from a snapshot by first creating a disk from it, this is not designed for reusable deployments because a snapshot captures a specific state (often not generalized) and does not provide a clean, sysprepped, template-ready image. Snapshots also require an extra, indirect conversion step and lack the versioning and replication capabilities of a proper image, making them a poor choice for baseline VM provisioning.
When this WOULD be correct
When the goal is to create multiple VMs from the same OS disk state for disaster recovery or testing, and you plan to attach the snapshot as a disk to a new VM, or when you need to quickly restore a specific disk to a VM without preserving other VM-level settings.
- ✗
An availability set
Why it's wrong here
An availability set is a logical placement container that Azure uses to distribute the VMs it contains across multiple fault domains and update domains, thereby protecting against hardware failures and planned maintenance downtime. It entirely concerns the physical and logical redundancy of VM placement—it has no bearing on the operating system, disk contents, or software installed on each VM. While adding a VM to an availability set improves resiliency, it does not influence the initial configuration or software image that the VM boots from.
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 custom imageCorrect answer▾
Why this is correct
A custom image is a generalized virtual hard disk (VHD) or managed image that contains the operating system, preinstalled software, and configuration settings (e.g., Windows updates, system roles, local policies) captured from a prepared source VM. For Windows, the source VM is generalized using Sysprep to remove machine-specific identifiers, making the image reusable for creating any number of identical VMs. Deploying from a custom image is the standard, supported way to launch new VMs with the exact same baseline and organizational configuration.
✗A marketplace imageWrong answer — click to see why▾
Why this is wrong here
A marketplace image is a generic, pre-configured image provided by Azure or third parties, not a custom image based on an existing approved production VM. It does not include the specific custom software and configuration already present on that VM.
★ When this WOULD be the correct answer
When the question asks for deploying a VM using a standard, Microsoft-verified Windows Server image without any customizations, or when you need to quickly deploy a VM with common configurations and no requirement to replicate an existing VM's custom setup.
Why candidates choose this
Candidates may assume marketplace images are the easiest or default choice for any VM deployment, overlooking the requirement for custom software and configuration that only a custom image can provide.
✗A snapshot of the OS diskWrong answer — click to see why▾
Why this is wrong here
A snapshot captures the state of a disk at a point in time but is not directly deployable as a VM; it must first be converted to a managed disk or used to create a custom image, which adds extra steps and does not preserve the full VM configuration like network settings.
★ When this WOULD be the correct answer
When the goal is to create multiple VMs from the same OS disk state for disaster recovery or testing, and you plan to attach the snapshot as a disk to a new VM, or when you need to quickly restore a specific disk to a VM without preserving other VM-level settings.
Why candidates choose this
Candidates may think a snapshot is equivalent to a custom image because both capture disk state, but they overlook that a snapshot lacks the generalized system preparation and VM-specific metadata required for direct deployment of a new VM with identical 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?”
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Courseiva writes every AZ-104 question from scratch — 1,049 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or dumps. Learn why practice questions differ from exam dumps →
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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.