AZ-305 Design business continuity solutions Practice Question
A company runs a critical application on Azure VMs in a single region. They need to implement disaster recovery using Azure Site Recovery (ASR) with a recovery point objective (RPO) of 15 minutes and a recovery time objective (RTO) of 2 hours. The database VMs have a very high data change rate, and the company wants to minimize replication costs. They also need to ensure that in the recovery plan, database VMs start before application VMs, and a script updates DNS records after failover. Which combination of ASR configurations should they use?
⚠ Common exam trap
A common mix-up: candidates assume app-consistent replication is always required for database VMs, but the question explicitly prioritizes minimizing replication costs and only requires a 15-minute RPO, making crash-consistent replication the correct choice despite the high data change rate.
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
✓
Enable crash-consistent replication and use recovery plans with pre- and post-actions.
Crash-consistent replication is the most cost-effective ASR option for VMs with high data change rates, as it replicates only the data that has changed since the last snapshot without requiring application-level consistency. The RPO of 15 minutes and RTO of 2 hours can be met with crash-consistent replication, and recovery plans with pre- and post-actions allow you to specify that database VMs start before application VMs and run a script to update DNS records after failover.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Enable multi-VM consistency groups and use recovery plans with manual ordering.
Why it's wrong here
Multi-VM consistency groups in Azure Site Recovery are intended for on-premises VMware/Physical machines, not for Azure-VM-to-Azure-VM replication, so they do not apply to this critical Azure VM workload. Manual ordering of recovery plan groups only controls the order in which VMs start or stop; it cannot run the required post-failover configuration scripts or automate application initialization. This approach adds complexity and cost without delivering the desired automation, so it does not meet the response requirement.
- ✗
Enable app-consistent replication and use deployment plans with pre- and post-actions.
Why it's wrong here
App-consistent replication in Azure Site Recovery invokes VSS to freeze application I/O and create transactionally consistent snapshots, which adds disk and CPU overhead and can fail on high-change databases; it is unnecessary if a crash-consistent recovery point satisfies the RPO. 'Deployment plans' are not a feature in Azure Site Recovery — the correct mechanism is a recovery plan, which supports pre-actions and post-actions for controlling VM startup and running scripts. Combining app-consistent replication with an improperly named component would increase cost and still rely on the wrong orchestration tool, so this option is invalid.
- ✗
Enable replication with high churn protection and use recovery plans with availability groups.
Why it's wrong here
High churn protection is not a real Azure Site Recovery feature; ASR only exposes churn metrics for monitoring and does not offer a special replication mode with that name. Recovery plans in ASR cannot use SQL Server availability groups as an ordering mechanism — availability groups are a database-level high-availability feature and have no bearing on VM startup sequencing or script execution. Choosing this option would neither minimize cost nor automate the required failover steps, making it incorrect.
- ✓
Enable crash-consistent replication and use recovery plans with pre- and post-actions.
Why this is correct
Crash-consistent replication in Azure Site Recovery copies all disks without invoking VSS, avoiding application-level snapshot overhead while still generating recovery points at the OS level; for this critical workload, those recovery points meet the stipulated RPO and reduce storage and I/O costs. A recovery plan groups VMs into ordered clauses, and you add pre-actions to enforce startup order — for example, starting the database VM before the web VM — and post-actions to run PowerShell scripts after failover to complete application configuration. This combination provides the required automation with the least expensive replication mode, so it is the correct answer.
Visual reference
Go deeper
Related to this question
Learn chapter
Multi-Region Active-Active Architecture
Key term
BIA and RPO RTO Design
Business Impact Analysis and the design of Recovery Point Objective and Recovery Time Objective define how much data loss and downtime a business can tolerate after an IT failure, guiding the architecture of backup and disaster recovery systems.
Key term
Azure Site Recovery
Azure Site Recovery is a Microsoft Azure service that keeps your business applications and data running by automatically replicating them to a secondary location and failing over if the primary site goes down.
About these practice questions
One of 795 original AZ-305 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-305 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-305 exam.