AZ-104 Implement and Manage Storage Practice Question
A development team stores build artifacts in Azure Blob Storage. The artifacts must remain available if one datacenter in the Azure region fails, but the business does not want to pay for replication to another region. Which redundancy option should the administrator select?
⚠ Common exam trap
A common mix-up: candidates confuse ZRS with LRS, thinking LRS provides zone-level redundancy because it uses three copies, but LRS copies are within a single datacenter, not across zones.
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 distributes copies across availability zones within the same region.
B is correct because Zone-Redundant Storage (ZRS) synchronously replicates data across three Azure availability zones within the same region, ensuring durability even if one entire datacenter (zone) fails. This meets the requirement of intra-region resilience without incurring the cost of geo-replication to another region.
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 multiple copies in the same zone and is the cheapest option.
Why it's wrong here
LRS is incorrect because it maintains three synchronous replicas within a single data center (or storage scale unit) in the same region. It protects against individual disk or server failures but offers no protection from a datacenter-wide or availability-zone outage. Although it is the cheapest option, its availability is tied to one physical facility, so it cannot satisfy the requirement to survive a datacenter failure within the region.
When this WOULD be correct
LRS would be correct if the question specified that the data must be protected only against hardware failures within a single datacenter (e.g., disk or server failures) and cost minimization is the primary concern, with no requirement for datacenter-level failure protection.
- ✓
ZRS, because it distributes copies across availability zones within the same region.
Why this is correct
ZRS is the right choice when you want resilience to a datacenter or zone failure within a region without paying for geo-replication. It stores copies across multiple availability zones, which improves availability while keeping the data in a single region. That matches the requirement to stay regional but survive a datacenter outage.
- ✗
GRS, because it keeps the workload available in two regions at all times.
Why it's wrong here
GRS is wrong because it replicates data to a paired secondary region, which goes beyond the stated requirement to stay within one region and incurs extra storage and egress costs. It also has a critical gap for this scenario: the copy in the primary region is LRS, not ZRS, so a single zone failure in the primary region would still make the data unavailable until a failover is initiated. Thus, GRS provides geo-redundancy, not the specific zone-level resilience the requirement demands.
When this WOULD be correct
Select GRS when the requirement is to protect against a region-wide outage by replicating data to a paired secondary region, and the business accepts the additional cost for cross-region disaster recovery.
- ✗
RA-GRS, because it provides zone redundancy and read access in the secondary region.
Why it's wrong here
RA-GRS is incorrect because the 'RA' prefix stands for read-access geo-redundant storage, not zone redundancy. It replicates data to a paired secondary region asynchronously and grants read access to that secondary copy, but the primary region still uses LRS, meaning data is not distributed across availability zones. This fails the requirement to remain in a single region and does not protect against an availability zone outage within the primary region.
When this WOULD be correct
A question requiring read access to data during a regional outage, with the business willing to pay for cross-region replication, would make RA-GRS correct. For example: 'Users need read access to blobs if the primary region fails; cost is not a concern.'
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 distributes copies across availability zones within the same region.Correct answer▾
Why this is correct
ZRS is the right choice when you want resilience to a datacenter or zone failure within a region without paying for geo-replication. It stores copies across multiple availability zones, which improves availability while keeping the data in a single region. That matches the requirement to stay regional but survive a datacenter outage.
✗LRS, because it keeps multiple copies in the same zone and is the cheapest option.Wrong answer — click to see why▾
Why this is wrong here
LRS only replicates data within a single datacenter, so if that datacenter fails, the artifacts become unavailable. The question requires availability if one datacenter fails, which ZRS provides by replicating across multiple availability zones within the region.
★ When this WOULD be the correct answer
LRS would be correct if the question specified that the data must be protected only against hardware failures within a single datacenter (e.g., disk or server failures) and cost minimization is the primary concern, with no requirement for datacenter-level failure protection.
Why candidates choose this
Candidates may choose LRS because it is the cheapest option and they incorrectly assume that 'one datacenter failure' refers to a single server or rack, not an entire datacenter, or they confuse LRS with zone-level redundancy.
✗GRS, because it keeps the workload available in two regions at all times.Wrong answer — click to see why▾
Why this is wrong here
GRS replicates data to a secondary region, incurring cross-region costs, but the question explicitly states the business does not want to pay for replication to another region.
★ When this WOULD be the correct answer
Select GRS when the requirement is to protect against a region-wide outage by replicating data to a paired secondary region, and the business accepts the additional cost for cross-region disaster recovery.
Why candidates choose this
Candidates may think GRS provides the highest availability and mistakenly choose it without reading the cost constraint, or they confuse 'region' with 'datacenter' and assume GRS is needed for a single datacenter failure.
✗RA-GRS, because it provides zone redundancy and read access in the secondary region.Wrong answer — click to see why▾
Why this is wrong here
RA-GRS replicates to a paired secondary region (geo-redundancy), not within the same region, so it does not meet the requirement to avoid cross-region replication costs.
★ When this WOULD be the correct answer
A question requiring read access to data during a regional outage, with the business willing to pay for cross-region replication, would make RA-GRS correct. For example: 'Users need read access to blobs if the primary region fails; cost is not a concern.'
Why candidates choose this
Candidates may confuse 'zone' with 'region' and think RA-GRS provides zone redundancy, or they focus on the 'read access' feature without noting the cross-region replication requirement.
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?”
Quick reference
Azure Blob Storage Tier Comparison
| Tier | Storage Cost | Retrieval Cost | Latency | Use Case |
|---|---|---|---|---|
| Hot | Highest | Lowest | Immediate | Active data, frequent reads |
| Cool | Lower | Higher | Immediate | Data accessed < once / month |
| Cold | Lower still | Higher | Immediate | Data accessed < once / quarter |
| Archive | Lowest | Highest + rehydration delay | Hours | Long-term compliance retention |
Go deeper
Related to this question
Learn chapter
Managed Identities for Azure Resources
Key term
Blob
A blob is a large piece of unstructured data, like a photo or video, stored in the cloud with a unique identifier.
Key term
Availability
Availability is the measure of how often a system or service is operational and accessible when needed, typically expressed as a percentage of uptime.
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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.