AZ-104 Implement and Manage Storage Practice Question
An application writes transaction logs to a storage account in a region that supports availability zones. The business wants the account to stay available if one datacenter or zone fails, but it does not need a secondary region replica. Which redundancy option should you choose?
⚠ Common exam trap
A common mix-up: candidates confuse LRS's three-copy replication within one datacenter as sufficient for zone failures, not realizing that a zone can contain multiple datacenters and LRS does not span zones, while ZRS is specifically designed for zone-level resilience.
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
✓
ZRS, because it replicates synchronously across zones in the same region and survives a zone outage.
B is correct because Zone-Redundant Storage (ZRS) synchronously replicates data across three Azure availability zones within the same region. This design ensures that if one datacenter or zone fails, the storage account remains available and durable without requiring a secondary region replica, exactly matching the business requirement.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
LRS, because it keeps three copies within a single datacenter and is enough for any zone failure.
Why it's wrong here
LRS keeps three synchronous copies of data within a single physical datacenter, which protects against disk or server failures but not against a complete datacenter or zone outage. Because all three replicas reside in the same availability zone, that zone's failure takes down every copy, violating the requirement to survive a zone failure. The storage account would be unavailable and data might be lost until recovery.
When this WOULD be correct
LRS would be correct if the question specified that the storage account is in a region without availability zones, or if the requirement was to protect against individual disk failures within a single datacenter, with no need for zone-level resilience.
- ✓
ZRS, because it replicates synchronously across zones in the same region and survives a zone outage.
Why this is correct
ZRS keeps data synchronously replicated across multiple availability zones within one region. That design helps the storage account remain available when a zone or datacenter becomes unavailable, which matches the requirement. It avoids the added complexity and cost of geo-replication because a secondary region is not required.
- ✗
GRS, because it adds a geographically replicated secondary region for disaster recovery.
Why it's wrong here
GRS replicates data asynchronously to a paired secondary region, but its primary-region data is still protected by LRS only, meaning all copies can be lost or become unavailable if the primary zone fails. Geo-redundancy addresses entire-region disasters, not a zone outage, and asynchronous replication introduces a recovery point objective (RPO) that could lose recent transaction logs. For this requirement, a zone-redundant primary with synchronous replication within the region is needed.
When this WOULD be correct
Choose GRS when the business requires data durability and availability even during a region-wide disaster, and is willing to pay for geo-redundancy. For example, a financial application that must survive a complete regional outage.
- ✗
RA-GRS, because read access to the secondary region is the best protection against a zone failure.
Why it's wrong here
RA-GRS provides read-only access to a secondary region copy, but that copy is geo-redundant and asynchronously replicated; the primary copy itself is stored with LRS, so it is still vulnerable to a single-zone failure. Read actions from the secondary do not make the application's write operations resilient to a zone outage, nor do they guarantee the latest transaction logs are available. The scenario calls for zone-level tolerance within the same region, not a separate-region read endpoint.
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.
✓ZRS, because it replicates synchronously across zones in the same region and survives a zone outage.Correct answer▾
Why this is correct
ZRS keeps data synchronously replicated across multiple availability zones within one region. That design helps the storage account remain available when a zone or datacenter becomes unavailable, which matches the requirement. It avoids the added complexity and cost of geo-replication because a secondary region is not required.
✗LRS, because it keeps three copies within a single datacenter and is enough for any zone failure.Wrong answer — click to see why▾
Why this is wrong here
LRS replicates data three times within a single datacenter, so it cannot survive a zone failure because an entire zone (which includes multiple datacenters) could be lost.
★ When this WOULD be the correct answer
LRS would be correct if the question specified that the storage account is in a region without availability zones, or if the requirement was to protect against individual disk failures within a single datacenter, with no need for zone-level resilience.
Why candidates choose this
Candidates may think that three copies in one datacenter provide sufficient redundancy, not realizing that a zone failure can take out the entire datacenter, and LRS does not span zones.
✗GRS, because it adds a geographically replicated secondary region for disaster recovery.Wrong answer — click to see why▾
Why this is wrong here
GRS replicates data to a secondary region, but the question explicitly states that a secondary region replica is not needed. The requirement is only to survive a zone failure within the same region, which ZRS handles.
★ When this WOULD be the correct answer
Choose GRS when the business requires data durability and availability even during a region-wide disaster, and is willing to pay for geo-redundancy. For example, a financial application that must survive a complete regional outage.
Why candidates choose this
Candidates may think that more redundancy (geo-replication) is always better, overlooking the specific requirement that only zone-level failure protection is needed, not regional disaster recovery.
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?”
Go deeper
Related to this question
Learn chapter
Managed Identities for Azure Resources
Key term
Zone-redundant storage
Zone-redundant storage is a data replication method that stores copies of your data in multiple physical locations within a cloud region, so your data remains safe and available even if one entire data center fails.
Key term
Region
A region is a distinct geographic location where a cloud provider operates multiple data centers that are connected by low-latency networks and provide cloud services.
About these practice questions
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.