AZ-400 ARM deployment mode for partial updates Practice Question
Your YAML pipeline uses the 'AzureResourceManagerTemplateDeployment' task to deploy ARM templates. You need to handle incremental deployments and ensure that the task fails if any resource already exists and cannot be updated. Which deployment mode should you specify?
⚠ Common exam trap
Watch out — candidates often confuse 'Incremental' with 'Complete' mode, mistakenly thinking 'Complete' is safer for incremental updates, when in fact 'Complete' can delete resources not in the template, leading to data loss.
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
✓
Incremental
The 'Incremental' deployment mode in the AzureResourceManagerTemplateDeployment task handles only changes specified in the template, leaving existing resources unchanged. If a resource already exists and cannot be updated (e.g., due to a property conflict or immutable resource), the deployment fails, meeting the requirement to fail on such conflicts. This mode is the standard for additive, non-destructive ARM template deployments.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Incremental
Why this is correct
Incremental mode is the default ARM deployment mode that only adds, updates, or deletes resources that are specified in the template, leaving all other resources in the resource group untouched. This allows users to perform partial updates by modifying only the relevant resources without affecting the entire resource group's existing configuration.
- ✗
Complete
Why it's wrong here
Complete mode is an ARM deployment mode that deletes resources in the resource group that are not present in the template, which is destructive and not suitable for partial updates as it removes any undeclared resources. Using Complete mode for a partial update would inadvertently delete existing resources that were not included in the template, causing unintended downtime or data loss.
- ✗
Validate
Why it's wrong here
Validate is not an actual deployment mode but rather a pre-deployment operation that checks a template for syntax and semantic errors before submitting it to Azure. It does not create or modify any resources, so it cannot be used to perform partial updates or any changes to a resource group.
- ✗
CreateOrUpdate
Why it's wrong here
CreateOrUpdate is a REST API operation for individual resources rather than an ARM deployment mode for a whole template, and it only creates a new resource or updates an existing one without affecting other resources. Since ARM deployment modes are only Incremental or Complete when deploying a template, CreateOrUpdate is not a valid choice for managing partial updates across a resource group.
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-400 exam frequently reuses these exact scenarios with slightly different constraints.
✓IncrementalCorrect answer▾
Why this is correct
Incremental mode is the default ARM deployment mode that only adds, updates, or deletes resources that are specified in the template, leaving all other resources in the resource group untouched. This allows users to perform partial updates by modifying only the relevant resources without affecting the entire resource group's existing configuration.
✗CompleteWrong answer — click to see why▾
Why this is wrong here
Complete mode deletes resources not in the template; it does not fail on existing resources that cannot be updated.
✗ValidateWrong answer — click to see why▾
Why this is wrong here
Validate mode only validates the template without actually deploying resources.
✗CreateOrUpdateWrong answer — click to see why▾
Why this is wrong here
There is no deployment mode named 'CreateOrUpdate'; it is a behavior of Incremental mode.
Analysis generated from the official AZ-400blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Go deeper
Related to this question
Learn chapter
Designing a Build Pipeline
Key term
ARM template
An ARM template is a JSON file that defines the infrastructure and configuration for Azure resources, enabling repeatable and consistent deployments.
Key term
Task
A Task in Azure DevOps is a predefined, reusable step that performs a specific action during a build or release pipeline, like compiling code or running tests.
About these practice questions
One of 823 original AZ-400 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. 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-400 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-400 exam.