AZ-104 Implement and Manage Storage Practice Question
A company stores customer documents in Azure Blob Storage. The business requires the data to stay available if one availability zone in the region has an outage. Which redundancy option should the administrator choose?
⚠ Common exam trap
Watch out — candidates often confuse 'zone redundancy' with 'geo-redundancy' and pick GRS or RA-GRS, not realizing that those options protect against region-wide outages, not zone-level failures within a single region.
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
✓
Zone-redundant storage (ZRS)
Zone-redundant storage (ZRS) replicates data synchronously across three Azure availability zones within a primary region, ensuring data remains accessible if one zone fails. This meets the requirement for intra-region zone-level fault tolerance without the cost or complexity of geo-replication.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Locally redundant storage (LRS)
Why it's wrong here
Locally redundant storage (LRS) writes three synchronous copies to a single physical datacenter, protecting against node and rack failures but providing zero protection if the entire datacenter or the availability zone housing that datacenter fails. Since the question requires resilience to a zone outage, LRS would leave your customer documents inaccessible if that zone goes down, even though the data is still intact. With a durability of 11 nines and the lowest cost, LRS is a baseline option but does not meet the zone-level resilience requirement.
When this WOULD be correct
LRS would be correct if the requirement is to protect against server rack or disk failures within a single datacenter, and cost minimization is prioritized over zone-level resilience.
- ✓
Zone-redundant storage (ZRS)
Why this is correct
Zone-redundant storage (ZRS) is the correct choice because it synchronously replicates your data across three availability zones within the same Azure region. If a single zone fails, the Blob Storage endpoints remain available because the other zones continue serving requests, and data is still durable with no manual failover required. ZRS achieves high availability (99.99% SLA) and durability (12 nines) while keeping the performance and access characteristics identical to using a single regional endpoint.
- ✗
Geo-redundant storage (GRS)
Why it's wrong here
Geo-redundant storage (GRS) replicates data asynchronously to a paired secondary region, which protects against region-wide disasters but not against an availability zone outage in the primary region. Even though your data is copied off-site, the primary Blob Storage endpoint is still down after a zone failure, and you must wait for a Microsoft-initiated or customer-initiated failover to the secondary region before accessing data. GRS also uses an LRS replica in both regions, so it does not inherently provide synchronous cross-zone availability within your primary region.
When this WOULD be correct
A company requires data to survive a complete regional outage (e.g., due to a natural disaster) and can tolerate a longer recovery time. The question would specify 'region failure' instead of 'availability zone failure'.
- ✗
Read-access geo-redundant storage (RA-GRS)
Why it's wrong here
Read-access geo-redundant storage (RA-GRS) extends GRS by allowing read access to the secondary-region copy while the primary region is available. However, during a zone outage in the primary region, the secondary copy is still read-only and write operations remain unavailable unless a failover is performed to promote the secondary to the writable region. This option was designed for disaster recovery with read access, not for maintaining continuous, writable availability when one availability zone in the primary region fails—so it fails the stated zone-failure requirement.
When this WOULD be correct
RA-GRS would be correct if the question required data to remain available during a region-wide outage and also needed read access to the secondary region for disaster recovery or compliance purposes, such as 'A company needs to ensure data is readable from a secondary region if the primary region fails.'
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.
✓Zone-redundant storage (ZRS)Correct answer▾
Why this is correct
Zone-redundant storage (ZRS) is the correct choice because it synchronously replicates your data across three availability zones within the same Azure region. If a single zone fails, the Blob Storage endpoints remain available because the other zones continue serving requests, and data is still durable with no manual failover required. ZRS achieves high availability (99.99% SLA) and durability (12 nines) while keeping the performance and access characteristics identical to using a single regional endpoint.
✗Locally redundant storage (LRS)Wrong answer — click to see why▾
Why this is wrong here
LRS replicates data within a single availability zone, so it cannot survive an entire zone outage, which is the requirement in this question.
★ When this WOULD be the correct answer
LRS would be correct if the requirement is to protect against server rack or disk failures within a single datacenter, and cost minimization is prioritized over zone-level resilience.
Why candidates choose this
Candidates may confuse LRS as sufficient because it provides local redundancy, overlooking that it does not span multiple zones, which is needed for zone outage protection.
✗Geo-redundant storage (GRS)Wrong answer — click to see why▾
Why this is wrong here
Geo-redundant storage (GRS) replicates data to a secondary region, not within the same region's availability zones. It protects against region-wide outages, not zone failures within a single region.
★ When this WOULD be the correct answer
A company requires data to survive a complete regional outage (e.g., due to a natural disaster) and can tolerate a longer recovery time. The question would specify 'region failure' instead of 'availability zone failure'.
Why candidates choose this
Candidates may confuse 'redundancy' with 'geo-redundancy', assuming that any multi-site replication provides zone-level protection, or they may over-engineer the solution without reading the requirement for zone-specific resilience.
✗Read-access geo-redundant storage (RA-GRS)Wrong answer — click to see why▾
Why this is wrong here
RA-GRS provides read access to a secondary region, but the question requires availability during an availability zone outage within the same region, not a regional disaster. RA-GRS does not protect against zone failures because it relies on regional replication, not zone-level redundancy.
★ When this WOULD be the correct answer
RA-GRS would be correct if the question required data to remain available during a region-wide outage and also needed read access to the secondary region for disaster recovery or compliance purposes, such as 'A company needs to ensure data is readable from a secondary region if the primary region fails.'
Why candidates choose this
Candidates may confuse 'availability zone outage' with 'regional outage' and think RA-GRS offers higher availability, or they may overvalue the read-access feature without considering the specific failure scenario described.
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
Availability zone
An Availability Zone is a distinct, isolated location within a cloud region that contains its own power, cooling, and networking, designed to protect applications from single points of failure.
Key term
ZRS
ZRS (Zone Redundant Storage) is a data storage option in Microsoft Azure that automatically replicates your data across multiple physical locations within a single region to keep it safe even if an entire data center goes down.
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 →
Same concept, more angles
1 more way this is tested on AZ-104
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A company hosts documents in Azure Blob Storage. The files must remain available if one availability zone in the region fails. Which redundancy option should the administrator choose?
easy- A.LRS, because it keeps three copies within one datacenter.
- ✓ B.ZRS, because it stores copies across multiple availability zones in the region.
- C.GRS, because it automatically makes the account available in another region for reads.
- D.RA-GRS, because it is the only option that keeps a secondary copy.
Why B: B is correct because Zone-Redundant Storage (ZRS) synchronously replicates data across three Azure availability zones within a primary region, ensuring data remains accessible if one zone fails. This meets the requirement for high availability within a single region without relying on a secondary region.
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.