AZ-104 Implement and Manage Storage Practice Question
Before changing a managed data disk on a production VM, you want a point-in-time copy that you can keep and restore later if needed. What should you create?
⚠ Common exam trap
Many candidates confuse a resource lock (which protects against deletion but does not create a copy) with a backup mechanism, or think an availability set provides data redundancy, when in fact only a snapshot or backup service captures a point-in-time copy of the disk.
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 managed disk snapshot
A managed disk snapshot captures a point-in-time, read-only copy of a managed disk. You can use it to restore the VM to that exact state by creating a new disk from the snapshot and attaching it to the VM. Snapshots are independent of the source disk's lifecycle, so you can keep them indefinitely for backup or recovery purposes.
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 managed disk snapshot
Why this is correct
A snapshot captures a point-in-time copy of a managed disk. It is the right choice when you want a recoverable copy before making changes. You can create it for an OS disk or data disk and use it later to restore or create a new disk if the original change does not work as expected.
- ✗
An availability set
Why it's wrong here
An availability set is a logical grouping of virtual machines that ensures they are placed across different fault domains and update domains, protecting the workload from hardware failures and planned maintenance. Its purpose is to maintain service uptime and meet the Azure SLA, not to capture or preserve disk state. No copy of the data disk is created, so an availability set offers no mechanism for reverting to a previous disk configuration after a change.
When this WOULD be correct
When the question asks for a feature that ensures VMs are distributed across fault domains and update domains to maintain availability during Azure maintenance events, an availability set is the correct answer.
- ✗
A load balancer backend pool
Why it's wrong here
A load balancer backend pool is a network-layer configuration that contains the VM IP addresses on which the load balancer forwards incoming traffic. It is used solely for distributing traffic and enabling resilience for network services; it has no visibility into disk contents, file systems, or storage operations. Adding a VM to a backend pool does not generate any disk image or snapshot, and therefore cannot be used to restore a managed data disk after an unwanted change.
When this WOULD be correct
When the question asks: 'You need to ensure that incoming traffic to a set of VMs is distributed evenly. What should you configure?' In that context, a load balancer backend pool is the correct answer.
- ✗
A resource lock
Why it's wrong here
A resource lock, such as a CanNotDelete or ReadOnly lock, is an Azure Resource Manager (ARM) management-plane control that prevents accidental deletion or modification of the VM or its resources. However, a lock does not intercept or copy any bits from the managed disk; it only enforces access restrictions on the resource itself. Consequently, it cannot provide a point-in-time disk image or rollback point for data that will be changed on the data disk.
When this WOULD be correct
A resource lock would be correct if the question asked: 'You want to prevent accidental deletion of a critical VM. What should you create?' In that scenario, a resource lock (e.g., CanNotDelete) is the appropriate solution.
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 managed disk snapshotCorrect answer▾
Why this is correct
A snapshot captures a point-in-time copy of a managed disk. It is the right choice when you want a recoverable copy before making changes. You can create it for an OS disk or data disk and use it later to restore or create a new disk if the original change does not work as expected.
✗An availability setWrong answer — click to see why▾
Why this is wrong here
An availability set is a logical grouping of VMs to ensure high availability during planned or unplanned maintenance, not a mechanism for creating point-in-time copies of disks.
★ When this WOULD be the correct answer
When the question asks for a feature that ensures VMs are distributed across fault domains and update domains to maintain availability during Azure maintenance events, an availability set is the correct answer.
Why candidates choose this
Candidates may confuse 'availability' with 'backup' or think that an availability set provides data redundancy or snapshots, misunderstanding its purpose as a high-availability construct.
✗A load balancer backend poolWrong answer — click to see why▾
Why this is wrong here
A load balancer backend pool is a configuration for distributing traffic across VMs, not a mechanism for creating point-in-time copies of a managed disk. It cannot be used to restore a disk to a previous state.
★ When this WOULD be the correct answer
When the question asks: 'You need to ensure that incoming traffic to a set of VMs is distributed evenly. What should you configure?' In that context, a load balancer backend pool is the correct answer.
Why candidates choose this
Candidates may confuse the concept of 'backup' with 'load balancing' or think that a backend pool provides redundancy that could serve as a restore point, misunderstanding the purpose of load balancers.
✗A resource lockWrong answer — click to see why▾
Why this is wrong here
A resource lock prevents accidental deletion or modification of a resource, but it does not create a point-in-time copy of a managed disk. The question specifically requires a copy that can be restored later, which only a snapshot provides.
★ When this WOULD be the correct answer
A resource lock would be correct if the question asked: 'You want to prevent accidental deletion of a critical VM. What should you create?' In that scenario, a resource lock (e.g., CanNotDelete) is the appropriate solution.
Why candidates choose this
Candidates may confuse 'protecting' a resource with 'backing it up.' A resource lock seems like a safety measure, but it does not create a recoverable copy, leading to this incorrect choice.
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 →
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.