AZ-104 Deploy and Manage Azure Compute Practice Question
An Azure VM backup job starts failing immediately after protection is enabled. The error states that the VM agent is not ready. The VM was created from a custom image and no extensions have ever installed successfully. What should the administrator verify first?
⚠ Common exam trap
It's easy for candidates to assume the issue is a vault configuration or capacity problem, but the 'VM agent not ready' error specifically points to a missing or non-functional guest agent, which is a common oversight when using custom images.
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
✓
That the Azure VM Agent service is installed and running inside the guest OS.
The error 'VM agent not ready' indicates that the Azure Backup extension cannot communicate with the VM agent inside the guest OS. Since the VM was created from a custom image and no extensions have ever installed successfully, the most likely cause is that the Azure VM Agent service is not installed or not running. The agent is required for backup extensions to function, so verifying its status inside the guest OS is the first troubleshooting step.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
That the Recovery Services vault is in the same resource group as the VM.
Why it's wrong here
The physical location of the Recovery Services vault relative to the VM (or its resource group) does not influence the guest-agent readiness check that gates backup execution. While vault and VM often share a resource group for management convenience, the backup extension communicates with the VM Agent directly, regardless of resource group placement. A network or region mismatch might affect data transfer, but a resource-group mismatch is not a technical constraint in Azure Backup. So this setting would never be the first suspect for an immediate failure.
When this WOULD be correct
If the error message indicated that the backup job failed because the vault could not communicate with the VM due to network restrictions, and the question asked what to verify first, then checking that the vault is in the same resource group might be relevant if a resource group-level network security group is blocking traffic.
- ✓
That the Azure VM Agent service is installed and running inside the guest OS.
Why this is correct
Azure VM Backup depends on the VM guest agent to coordinate extensions and backup integration. If the agent is missing, stopped, or unhealthy, backup jobs can fail immediately with a readiness message. Verifying the agent state is the correct first troubleshooting step before looking at policy, retention, or vault configuration.
- ✗
That soft delete is enabled on the vault.
Why it's wrong here
Enabling soft delete on a Recovery Services vault protects against accidental deletion of backup data, but it has no role in the execution of new backup jobs. Soft delete only activates when a backup item or vault is deleted, retaining data for 14 days. An immediate backup failure is typically a pre-flight validation error, such as an unhealthy VM Agent, not a retention or deletion policy. Therefore, soft-delete status would not cause a new backup job to start failing.
When this WOULD be correct
If the question described a scenario where backup data was being deleted accidentally or a user wanted to recover deleted backup items, verifying that soft delete is enabled would be the correct first step to ensure recoverability.
- ✗
That the subscription has enough free Azure Backup storage capacity.
Why it's wrong here
Azure Backup storage is elastic and metered per use; there is no pre-allocated capacity that must be free before a backup job can run. The subscription's storage quota applies to Managed Disks or other storage resources, not to the backup vault's internal storage. An immediate job failure caused by a quota issue would normally show a billing or quota error, not a guest-agent readiness error. Thus, checking free capacity is a red herring when the VM Agent is the actual problem.
When this WOULD be correct
If the error message indicated insufficient storage quota or backup job failures due to capacity limits, then verifying free Azure Backup storage capacity would be the correct first step.
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.
✓That the Azure VM Agent service is installed and running inside the guest OS.Correct answer▾
Why this is correct
Azure VM Backup depends on the VM guest agent to coordinate extensions and backup integration. If the agent is missing, stopped, or unhealthy, backup jobs can fail immediately with a readiness message. Verifying the agent state is the correct first troubleshooting step before looking at policy, retention, or vault configuration.
✗That the Recovery Services vault is in the same resource group as the VM.Wrong answer — click to see why▾
Why this is wrong here
The error specifically states the VM agent is not ready, which is a guest OS issue, not a resource group placement issue. The Recovery Services vault can be in a different resource group than the VM and still function correctly.
★ When this WOULD be the correct answer
If the error message indicated that the backup job failed because the vault could not communicate with the VM due to network restrictions, and the question asked what to verify first, then checking that the vault is in the same resource group might be relevant if a resource group-level network security group is blocking traffic.
Why candidates choose this
Candidates may mistakenly think that Azure resources must be in the same resource group to interact, confusing resource group scope with functional connectivity requirements.
✗That soft delete is enabled on the vault.Wrong answer — click to see why▾
Why this is wrong here
Soft delete is a data protection feature that prevents accidental deletion of backup data, but it does not affect the VM agent readiness or backup job initiation. The error specifically indicates the VM agent is not responding, which is unrelated to soft delete settings.
★ When this WOULD be the correct answer
If the question described a scenario where backup data was being deleted accidentally or a user wanted to recover deleted backup items, verifying that soft delete is enabled would be the correct first step to ensure recoverability.
Why candidates choose this
Candidates may confuse soft delete with a prerequisite for backup success, thinking that enabling it is necessary for backup jobs to run, when in fact it only protects backup data after creation.
✗That the subscription has enough free Azure Backup storage capacity.Wrong answer — click to see why▾
Why this is wrong here
The error specifically states the VM agent is not ready, which is a guest OS issue, not a storage capacity issue. Backup storage capacity does not affect the VM agent's readiness.
★ When this WOULD be the correct answer
If the error message indicated insufficient storage quota or backup job failures due to capacity limits, then verifying free Azure Backup storage capacity would be the correct first step.
Why candidates choose this
Candidates may confuse general backup failures with capacity issues, assuming that lack of storage space could prevent backup jobs from starting.
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.