Azure Storage Redundancy: ZRS, GZRS, RA-GZRS, and More
You need a storage redundancy option that keeps data available if an entire availability zone in the primary region fails, but you do not need cross-region replication. Which redundancy option should you choose?
⚠ Common exam trap
It's easy for candidates to confuse ZRS with LRS, thinking LRS provides zone redundancy, but LRS only replicates within one data center, 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
B is correct because Zone-Redundant Storage (ZRS) synchronously replicates data across three Azure availability zones within a single region, ensuring data remains available if an entire zone fails. This meets the requirement of no cross-region replication while providing zone-level fault tolerance.
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
Why it's wrong here
LRS replicates three copies synchronously within a single datacentre, so a zone failure takes the data offline; it offers no zone-level resilience. It is the correct pick when only disk-level durability within one facility is required and cost must stay minimal.
- ✓
ZRS
Why this is correct
ZRS synchronously replicates data across three availability zones within a single primary region, so an entire zone failure leaves data accessible. It satisfies the stem's zone-failure requirement without the cost of cross-region replication, which GRS or GZRS would add unnecessarily.
- ✗
GRS
Why it's wrong here
GRS replicates data to a secondary region, which the scenario explicitly excludes, and its zone-failure protection within the primary region is not the design goal. GRS suits disaster recovery requiring regional durability; zone-redundant storage is the option that survives an availability zone loss without cross-region replication.
When this WOULD be correct
A question that asks for a redundancy option that keeps data available if an entire region fails, and requires cross-region replication for disaster recovery, would make GRS the correct answer. For example: 'You need to ensure data is available even if the primary region becomes unavailable due to a regional disaster. Which redundancy option should you choose?'
- ✗
RA-GRS
Why it's wrong here
RA-GRS replicates asynchronously to a secondary region, so a zone failure in the primary region is covered by LRS within that region, not by the geo-replica. It is tempting when read access to a paired region is genuinely required.
When this WOULD be correct
A question asks: 'You need to ensure that data remains readable from a secondary region if the primary region becomes unavailable, and you want to minimize cost. Which redundancy option should you choose?' In that scenario, RA-GRS would be correct because it provides read-only access to the secondary region at a lower cost than GRS.
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.
✓ZRSCorrect answer▾
Why this is correct
ZRS synchronously replicates data across three availability zones within a single primary region, so an entire zone failure leaves data accessible. It satisfies the stem's zone-failure requirement without the cost of cross-region replication, which GRS or GZRS would add unnecessarily.
✗GRSWrong answer — click to see why▾
Why this is wrong here
GRS replicates data to a paired secondary region, which provides cross-region replication. The question explicitly states that cross-region replication is not needed, so GRS is unnecessary and does not meet the requirement of keeping data available if an entire availability zone fails without cross-region replication.
★ When this WOULD be the correct answer
A question that asks for a redundancy option that keeps data available if an entire region fails, and requires cross-region replication for disaster recovery, would make GRS the correct answer. For example: 'You need to ensure data is available even if the primary region becomes unavailable due to a regional disaster. Which redundancy option should you choose?'
Why candidates choose this
Candidates may confuse zone-level failures with regional failures, or think that GRS provides zone redundancy within the primary region, not realizing that GRS is primarily for cross-region failover and does not protect against zone failures within the primary region.
✗RA-GRSWrong answer — click to see why▾
Why this is wrong here
RA-GRS provides read-access to a secondary region during a regional outage, but the question explicitly states that cross-region replication is not needed. Additionally, RA-GRS does not protect against an entire availability zone failure in the primary region because it relies on LRS within the primary region.
★ When this WOULD be the correct answer
A question asks: 'You need to ensure that data remains readable from a secondary region if the primary region becomes unavailable, and you want to minimize cost. Which redundancy option should you choose?' In that scenario, RA-GRS would be correct because it provides read-only access to the secondary region at a lower cost than GRS.
Why candidates choose this
Candidates may confuse RA-GRS with ZRS, thinking that read-access geo-redundancy provides zone-level protection, or they may overlook the constraint that cross-region replication is not required.
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
Azure Blob Storage Access Tiers
Key term
Cross-Region Replication
Cross-Region Replication is the automated copying of data from a storage bucket in one geographic region to a bucket in a different geographic region for disaster recovery, compliance, or lower latency access.
Key term
Replication
Replication is the process of copying and synchronizing data across multiple servers or storage devices to ensure availability, reliability, and fault tolerance.
About these practice questions
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Same concept, more angles
3 more ways 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 wants its file share data to be automatically copied to a paired Azure region, and administrators want to read the secondary copy during a disaster test. Which redundancy option should they use?
easy- A.ZRS
- B.LRS
- ✓ C.RA-GRS
- D.Cool
Why C: RA-GRS (Read-Access Geo-Redundant Storage) is correct because it replicates data to a paired secondary region asynchronously and provides read-only access to that secondary copy. This allows administrators to read the secondary copy during a disaster test without impacting the primary region. ZRS and LRS do not replicate to a paired region, and Cool is a tier, not a redundancy option.
Variation 2. An Azure Files share must stay available if one availability zone in its primary region fails. The business does not need replication to another region. Which redundancy option should you choose for the storage account?
easy- A.Locally redundant storage (LRS)
- ✓ B.Zone-redundant storage (ZRS)
- C.Geo-redundant storage (GRS)
- D.Read-access geo-redundant storage (RA-GRS)
Why B: Zone-redundant storage (ZRS) synchronously replicates your Azure Files share across three Azure availability zones within the primary region. This ensures the share remains available if one zone fails, without requiring replication to another region. LRS only replicates within a single data center, while GRS and RA-GRS involve secondary region replication, which the business does not need.
Variation 3. A team wants a storage option that stays available if one availability zone in the primary region fails. Which two redundancy options meet that requirement? Select two.
easy- ✓ A.Zone-redundant storage (ZRS).
- ✓ B.Geo-zone-redundant storage (GZRS).
- C.Locally redundant storage (LRS).
- D.Geo-redundant storage (GRS).
- E.Read-access geo-redundant storage (RA-GRS).
Why A: Zone-redundant storage (ZRS) synchronously replicates data across three Azure availability zones within the primary region. If one zone fails, the data remains accessible from the other zones, ensuring high availability without requiring failover to 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.